diff --git a/src/engine/gnc-engine.h b/src/engine/gnc-engine.h
index 1d0deab6cc..d4db2c1e34 100644
--- a/src/engine/gnc-engine.h
+++ b/src/engine/gnc-engine.h
@@ -256,5 +256,10 @@ void gnc_engine_signal_commit_error( QofBackendError errcode );
  */
 #define GNC_INVOICE_ID    "gncInvoice"
 #define GNC_INVOICE_GUID  "invoice-guid"
+#define GNC_OWNER_ID    "gncOwner"
+#define GNC_OWNER_TYPE  "owner-type"
+#define GNC_OWNER_GUID  "owner-guid"
+
+
 #endif
 /** @} */
diff --git a/src/engine/gnc-lot.c b/src/engine/gnc-lot.c
index d630b1d8c8..4b2bac4e3b 100644
--- a/src/engine/gnc-lot.c
+++ b/src/engine/gnc-lot.c
@@ -65,7 +65,11 @@ enum
 {
     PROP_0,
     PROP_IS_CLOSED,
-    PROP_MARKER
+    PROP_MARKER,
+
+    PROP_INVOICE,
+    PROP_OWNER_TYPE,
+    PROP_OWNER_GUID,
 };
 
 typedef struct LotPrivate
@@ -94,6 +98,11 @@ typedef struct LotPrivate
 
 /* ============================================================= */
 
+static void gnc_lot_set_invoice (GNCLot* lot, GncGUID *guid);
+static GncGUID *gnc_lot_get_invoice (GNCLot* lot);
+
+/* ============================================================= */
+
 /* GObject Initialization */
 G_DEFINE_TYPE(GNCLot, gnc_lot, QOF_TYPE_INSTANCE)
 
@@ -126,6 +135,9 @@ gnc_lot_get_property(GObject* object, guint prop_id, GValue* value, GParamSpec*
 {
     GNCLot* lot;
     LotPrivate* priv;
+    KvpFrame *frame;
+    gchar *key;
+    GValue *temp;
 
     g_return_if_fail(GNC_IS_LOT(object));
 
@@ -139,6 +151,21 @@ gnc_lot_get_property(GObject* object, guint prop_id, GValue* value, GParamSpec*
     case PROP_MARKER:
         g_value_set_int(value, priv->marker);
         break;
+    case PROP_INVOICE:
+	key = GNC_INVOICE_ID "/" GNC_INVOICE_GUID;
+	qof_instance_get_kvp (QOF_INSTANCE (lot), key, value);
+	break;
+    case PROP_OWNER_TYPE:
+	key = GNC_OWNER_ID"/" GNC_OWNER_TYPE;
+	qof_instance_get_kvp (QOF_INSTANCE (lot), key, value);
+	break;
+    case PROP_OWNER_GUID:
+	key = GNC_OWNER_ID "/" GNC_OWNER_GUID;
+	qof_instance_get_kvp (QOF_INSTANCE (lot), key, value);
+	break;
+    default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
+        break;
     }
 }
 
@@ -147,6 +174,8 @@ gnc_lot_set_property(GObject* object, guint prop_id, const GValue* value, GParam
 {
     GNCLot* lot;
     LotPrivate* priv;
+    KvpFrame *frame;
+    gchar *key = NULL;
 
     g_return_if_fail(GNC_IS_LOT(object));
 
@@ -160,7 +189,22 @@ gnc_lot_set_property(GObject* object, guint prop_id, const GValue* value, GParam
     case PROP_MARKER:
         priv->marker = g_value_get_int(value);
         break;
-    }
+    case PROP_INVOICE:
+	key = GNC_INVOICE_ID"/" GNC_INVOICE_GUID;
+	qof_instance_set_kvp (QOF_INSTANCE (lot), key, value);
+	break;
+    case PROP_OWNER_TYPE:
+	key = GNC_OWNER_ID "/" GNC_OWNER_TYPE;
+	qof_instance_set_kvp (QOF_INSTANCE (lot), key, value);
+	break;
+    case PROP_OWNER_GUID:
+	key = GNC_OWNER_ID "/" GNC_OWNER_GUID;
+	qof_instance_set_kvp (QOF_INSTANCE (lot), key, value);
+	break;
+    default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
+        break;
+     }
 }
 
 static void
@@ -194,8 +238,32 @@ gnc_lot_class_init(GNCLotClass* klass)
                          0, G_MAXINT8, 0,
                          G_PARAM_READWRITE));
 
+     g_object_class_install_property(
+       gobject_class,
+        PROP_INVOICE,
+        g_param_spec_boxed("invoice",
+			   "Invoice attached to lot",
+			   "Used by GncInvoice",
+			   GNC_TYPE_GUID,
+			   G_PARAM_READWRITE));
 
+     g_object_class_install_property(
+       gobject_class,
+        PROP_OWNER_TYPE,
+        g_param_spec_int64("owner-type",
+			   "Owning Entity Type of  lot",
+			   "Used by GncOwner",
+			   0, G_MAXINT64, 0,
+			   G_PARAM_READWRITE));
 
+     g_object_class_install_property(
+       gobject_class,
+        PROP_OWNER_GUID,
+        g_param_spec_boxed("owner-guid",
+			   "Owner attached to lot",
+			   "Used by GncOwner",
+			   GNC_TYPE_GUID,
+			   G_PARAM_READWRITE));
 }
 
 GNCLot *
diff --git a/src/engine/gncInvoice.c b/src/engine/gncInvoice.c
index 2ac268f12f..3972a4e713 100644
--- a/src/engine/gncInvoice.c
+++ b/src/engine/gncInvoice.c
@@ -82,8 +82,6 @@ static QofLogModule log_module = GNC_MOD_BUSINESS;
 
 #define _GNC_MOD_NAME     GNC_ID_INVOICE
 
-#define GNC_INVOICE_ID    "gncInvoice"
-#define GNC_INVOICE_GUID  "invoice-guid"
 #define GNC_INVOICE_IS_CN "credit-note"
 
 #define SET_STR(obj, member, str) { \
@@ -1080,52 +1078,37 @@ qofInvoiceSetJob (GncInvoice *invoice, GncJob *job)
 static void
 gncInvoiceDetachFromLot (GNCLot *lot)
 {
-    KvpFrame *kvp;
-
     if (!lot) return;
+
     gnc_lot_begin_edit (lot);
-    kvp = gnc_lot_get_slots (lot);
-    kvp_frame_set_slot_path (kvp, NULL, GNC_INVOICE_ID, GNC_INVOICE_GUID, NULL);
-    qof_instance_set_dirty (QOF_INSTANCE (lot));
+    qof_instance_set (QOF_INSTANCE (lot), "invoice", NULL, NULL);
     gnc_lot_commit_edit (lot);
 }
 
 static void
 gncInvoiceAttachToLot (GncInvoice *invoice, GNCLot *lot)
 {
-    KvpFrame *kvp;
-    KvpValue *value;
-
+    GncGUID *guid;
     if (!invoice || !lot)
         return;
 
     if (invoice->posted_lot) return;	/* Cannot reset invoice's lot */
-
+    guid  = (GncGUID*)qof_instance_get_guid (QOF_INSTANCE (invoice));
     gnc_lot_begin_edit (lot);
-    kvp = gnc_lot_get_slots (lot);
-    value = kvp_value_new_guid (qof_instance_get_guid (QOF_INSTANCE(invoice)));
-    kvp_frame_set_slot_path (kvp, value, GNC_INVOICE_ID, GNC_INVOICE_GUID, NULL);
-    qof_instance_set_dirty (QOF_INSTANCE (lot));
+    qof_instance_set (QOF_INSTANCE (lot), "invoice", guid, NULL);
     gnc_lot_commit_edit (lot);
-    kvp_value_delete (value);
     gncInvoiceSetPostedLot (invoice, lot);
 }
 
 GncInvoice * gncInvoiceGetInvoiceFromLot (GNCLot *lot)
 {
-    KvpFrame *kvp;
-    KvpValue *value;
     GncGUID *guid;
     QofBook *book;
 
     if (!lot) return NULL;
 
     book = gnc_lot_get_book (lot);
-    kvp = gnc_lot_get_slots (lot);
-    value = kvp_frame_get_slot_path (kvp, GNC_INVOICE_ID, GNC_INVOICE_GUID, NULL);
-    if (!value) return NULL;
-
-    guid = kvp_value_get_guid (value);
+    qof_instance_get (QOF_INSTANCE (lot), "invoice", &guid, NULL);
     return gncInvoiceLookup(book, guid);
 }
 
diff --git a/src/engine/gncInvoice.h b/src/engine/gncInvoice.h
index 4cd32b8731..b7a29c4c5a 100644
--- a/src/engine/gncInvoice.h
+++ b/src/engine/gncInvoice.h
@@ -251,6 +251,7 @@ GncInvoice * gncInvoiceGetInvoiceFromLot (GNCLot *lot);
  */
 static inline GncInvoice * gncInvoiceLookup (const QofBook *book, const GncGUID *guid)
 {
+    if (book == NULL || guid == NULL) return NULL;
     QOF_BOOK_RETURN_ENTITY(book, guid, GNC_ID_INVOICE, GncInvoice);
 }
 
@@ -288,7 +289,6 @@ QofBook *gncInvoiceGetBook(GncInvoice *x);
 /** deprecated functions */
 #define gncInvoiceGetGUID(x) qof_instance_get_guid(QOF_INSTANCE(x))
 #define gncInvoiceRetGUID(x) (x ? *(qof_instance_get_guid(QOF_INSTANCE(x))) : *(guid_null()))
-#define gncInvoiceLookupDirect(G,B) gncInvoiceLookup((B),&(G))
 
 /** Test support function used by test-dbi-business-stuff.c */
 gboolean gncInvoiceEqual(const GncInvoice *a, const GncInvoice *b);
diff --git a/src/engine/gncOwner.c b/src/engine/gncOwner.c
index c4ad44f505..ee2fa05b77 100644
--- a/src/engine/gncOwner.c
+++ b/src/engine/gncOwner.c
@@ -51,8 +51,6 @@
 #define _GNC_MOD_NAME   GNC_ID_OWNER
 
 #define GNC_OWNER_ID    "gncOwner"
-#define GNC_OWNER_TYPE  "owner-type"
-#define GNC_OWNER_GUID  "owner-guid"
 
 GncOwner * gncOwnerNew (void)
 {
@@ -568,31 +566,20 @@ const GncGUID * gncOwnerGetEndGUID (const GncOwner *owner)
 
 void gncOwnerAttachToLot (const GncOwner *owner, GNCLot *lot)
 {
-    KvpFrame *kvp;
-    KvpValue *value;
-
-    if (!owner || !lot)
+     if (!owner || !lot)
         return;
 
-    kvp = gnc_lot_get_slots (lot);
     gnc_lot_begin_edit (lot);
 
-    value = kvp_value_new_gint64 (gncOwnerGetType (owner));
-    kvp_frame_set_slot_path (kvp, value, GNC_OWNER_ID, GNC_OWNER_TYPE, NULL);
-    kvp_value_delete (value);
-
-    value = kvp_value_new_guid (gncOwnerGetGUID (owner));
-    kvp_frame_set_slot_path (kvp, value, GNC_OWNER_ID, GNC_OWNER_GUID, NULL);
-    qof_instance_set_dirty (QOF_INSTANCE (lot));
+    qof_instance_set (QOF_INSTANCE (lot),
+		      "owner-type", (gint64)gncOwnerGetType (owner),
+		      "owner-guid", gncOwnerGetGUID (owner),
+		      NULL);
     gnc_lot_commit_edit (lot);
-    kvp_value_delete (value);
-
 }
 
 gboolean gncOwnerGetOwnerFromLot (GNCLot *lot, GncOwner *owner)
 {
-    KvpFrame *kvp;
-    KvpValue *value;
     GncGUID *guid;
     QofBook *book;
     GncOwnerType type;
@@ -600,20 +587,10 @@ gboolean gncOwnerGetOwnerFromLot (GNCLot *lot, GncOwner *owner)
     if (!lot || !owner) return FALSE;
 
     book = gnc_lot_get_book (lot);
-    kvp = gnc_lot_get_slots (lot);
-
-    value = kvp_frame_get_slot_path (kvp, GNC_OWNER_ID, GNC_OWNER_TYPE, NULL);
-    if (!value) return FALSE;
-
-    type = kvp_value_get_gint64 (value);
-
-    value = kvp_frame_get_slot_path (kvp, GNC_OWNER_ID, GNC_OWNER_GUID, NULL);
-    if (!value) return FALSE;
-
-    guid = kvp_value_get_guid (value);
-    if (!guid)
-        return FALSE;
-
+    qof_instance_get (QOF_INSTANCE (lot),
+		      "owner-type", &type,
+		      "owner-guid", &guid,
+		      NULL);
     switch (type)
     {
     case GNC_OWNER_CUSTOMER:
diff --git a/src/engine/test/test-engine-kvp-properties.c b/src/engine/test/test-engine-kvp-properties.c
index ec0f3c5e82..ba74edd409 100644
--- a/src/engine/test/test-engine-kvp-properties.c
+++ b/src/engine/test/test-engine-kvp-properties.c
@@ -47,6 +47,7 @@ typedef struct
     {
 	Account      *acct;
 	Transaction  *trans;
+	GNCLot       *lot;
 	GncCustomer  *cust;
 	GncEmployee  *emp;
 	GncJob       *job;
@@ -77,6 +78,13 @@ setup_trans (Fixture *fixture, gconstpointer pData)
     fixture->trans = xaccMallocTransaction (book);
 }
 
+static void
+setup_lot (Fixture *fixture, gconstpointer pData)
+{
+    QofBook *book = qof_book_new ();
+    fixture->lot = gnc_lot_new (book);
+}
+
 static void
 teardown (Fixture *fixture, gconstpointer pData)
 {
@@ -130,8 +138,43 @@ test_trans_kvp_properties (Fixture *fixture, gconstpointer pData)
     guid_free (guid_r);
 }
 
+static void
+test_lot_kvp_properties (Fixture *fixture, gconstpointer pData)
+{
+    GncGUID *invoice = guid_malloc ();
+    GncGUID *invoice_r;
+    gint64 owner_type = 47;
+    gint64 owner_type_r;
+    GncGUID *owner = guid_malloc ();
+    GncGUID *owner_r;
+
+    qof_instance_set (QOF_INSTANCE (fixture->lot),
+		      "invoice", invoice,
+		      "owner-type", owner_type,
+		      "owner-guid", owner,
+		      NULL);
+
+    g_assert (qof_instance_is_dirty (QOF_INSTANCE (fixture->lot)));
+    qof_instance_mark_clean (QOF_INSTANCE (fixture->lot));
+
+    qof_instance_get (QOF_INSTANCE (fixture->lot),
+		      "invoice", &invoice_r,
+		      "owner-type", &owner_type_r,
+		      "owner-guid", &owner_r,
+		      NULL);
+    g_assert (guid_equal (invoice, invoice_r));
+    g_assert_cmpint (owner_type, ==, owner_type_r);
+    g_assert (guid_equal (owner, owner_r));
+    g_assert (!qof_instance_is_dirty (QOF_INSTANCE (fixture->lot)));
+    guid_free (invoice);
+    guid_free (invoice_r);
+    guid_free (owner);
+    guid_free (owner_r);
+}
+
 void test_suite_engine_kvp_properties (void)
 {
     GNC_TEST_ADD (suitename, "Account", Fixture, NULL, setup_account, test_account_kvp_properties, teardown);
     GNC_TEST_ADD (suitename, "Transaction", Fixture, NULL, setup_trans, test_trans_kvp_properties, teardown);
+    GNC_TEST_ADD (suitename, "Lot", Fixture, NULL, setup_lot, test_lot_kvp_properties, teardown);
 }