diff --git a/rattail_corepos/importing/corepos/api.py b/rattail_corepos/importing/corepos/api.py
index ed94bc0..92837ed 100644
--- a/rattail_corepos/importing/corepos/api.py
+++ b/rattail_corepos/importing/corepos/api.py
@@ -2,7 +2,7 @@
 ################################################################################
 #
 #  Rattail -- Retail Software Framework
-#  Copyright © 2010-2023 Lance Edgar
+#  Copyright © 2010-2024 Lance Edgar
 #
 #  This file is part of Rattail.
 #
@@ -32,9 +32,6 @@ from collections import OrderedDict
 from sqlalchemy import orm
 
 from rattail import importing
-from rattail.gpc import GPC
-from rattail.time import localtime, make_utc
-from rattail.core import get_uuid
 from rattail.db.util import normalize_full_name
 from rattail_corepos import importing as corepos_importing
 from rattail_corepos.corepos.util import get_core_members
@@ -68,7 +65,7 @@ class FromCOREPOSToRattail(importing.ToRattailHandler):
         return importers
 
     def get_default_keys(self):
-        keys = super(FromCOREPOSToRattail, self).get_default_keys()
+        keys = super().get_default_keys()
 
         if 'ProductMovement' in keys:
             keys.remove('ProductMovement')
@@ -410,7 +407,7 @@ class SubdepartmentImporter(FromCOREPOSAPI, corepos_importing.model.Subdepartmen
         return {
             'corepos_number': int(subdepartment['subdept_no']),
             'number': int(subdepartment['subdept_no']),
-            'name': subdepartment['subdept_name'],
+            'name': subdepartment.get('subdept_name'),
             'department_number': department_number,
         }
 
@@ -438,7 +435,7 @@ class VendorImporter(FromCOREPOSAPI, corepos_importing.model.VendorImporter):
         return {
             'corepos_id': int(vendor['vendorID']),
             'id': str(vendor['vendorID']),
-            'name': vendor['vendorName'],
+            'name': vendor.get('vendorName'),
             'abbreviation': vendor.get('vendorAbbreviation') or None,
             'special_discount': decimal.Decimal(vendor['discountRate']),
             'phone_number': vendor.get('phone') or None,
@@ -476,7 +473,7 @@ class ProductImporter(FromCOREPOSAPI, corepos_importing.model.ProductImporter):
     ]
 
     def setup(self):
-        super(ProductImporter, self).setup()
+        super().setup()
         model = self.model
 
         query = self.session.query(model.Product)\
@@ -496,6 +493,8 @@ class ProductImporter(FromCOREPOSAPI, corepos_importing.model.ProductImporter):
         self.progress_loop(cache, self.api.get_vendor_items(),
                            message="Caching CORE Vendor Items")
 
+        self.maxval_unit_size = self.app.maxval(model.Product.unit_size)
+
     def get_host_objects(self):
         return self.api.get_products()
 
@@ -528,7 +527,7 @@ class ProductImporter(FromCOREPOSAPI, corepos_importing.model.ProductImporter):
         product = self.identify_product(corepos_product)
         if product:
             return product.uuid
-        return get_uuid()
+        return self.app.make_uuid()
 
     def get_vendor_items(self, api_product):
         if hasattr(self, 'vendor_items_by_upc'):
@@ -537,8 +536,12 @@ class ProductImporter(FromCOREPOSAPI, corepos_importing.model.ProductImporter):
         return self.api.get_vendor_items(upc=api_product['upc'])
 
     def normalize_host_object(self, product):
+        if 'upc' not in product:
+            log.warning("CORE-POS product has no UPC: %s", product)
+            return
+
         try:
-            upc = GPC(product['upc'], calc_check_digit='upc')
+            upc = self.app.make_gpc(product['upc'], calc_check_digit='upc')
         except (TypeError, ValueError):
             log.debug("CORE POS product has invalid UPC: %s", product['upc'])
             if len(self.key) == 1 and self.key[0] == 'upc':
@@ -587,9 +590,14 @@ class ProductImporter(FromCOREPOSAPI, corepos_importing.model.ProductImporter):
                 'size': size_info['size'],
                 'unit_size': size_info['unit_size'],
                 'unit_of_measure': size_info['uom_code'],
-                'uom_abbreviation': size_info['uom_abbrev'],
+                'uom_abbreviation': (size_info['uom_abbrev'] or '').strip() or None,
             })
 
+            if data['unit_size'] and data['unit_size'] >= self.maxval_unit_size:
+                log.warning("unit_size too large (%s) for product %s, will use null instead: %s",
+                            data['unit_size'], data['upc'], product)
+                data['unit_size'] = None
+
         if 'case_size' in self.fields:
             case_size = None
             items = self.get_vendor_items(product)
@@ -633,8 +641,8 @@ class ProductMovementImporter(FromCOREPOSAPI, corepos_importing.model.ProductImp
         last_sold = None
         if 'last_sold' in product:
             last_sold = datetime.datetime.strptime(product['last_sold'], '%Y-%m-%d %H:%M:%S')
-            last_sold = localtime(self.config, last_sold)
-            last_sold = make_utc(last_sold)
+            last_sold = self.app.localtime(last_sold)
+            last_sold = self.app.make_utc(last_sold)
 
         return {
             'corepos_id': int(product['id']),
@@ -662,7 +670,7 @@ class ProductCostImporter(FromCOREPOSAPI, corepos_importing.model.ProductCostImp
     ]
 
     def setup(self):
-        super(ProductCostImporter, self).setup()
+        super().setup()
         model = self.config.get_model()
 
         query = self.session.query(model.Vendor)\
@@ -676,7 +684,8 @@ class ProductCostImporter(FromCOREPOSAPI, corepos_importing.model.ProductCostImp
         self.corepos_products = {}
 
         def cache(product, i):
-            self.corepos_products[product['upc']] = product
+            if 'upc' in product:
+                self.corepos_products[product['upc']] = product
 
         self.progress_loop(cache, self.api.get_products(),
                            message="Caching Products from CORE-POS API")
@@ -881,10 +890,10 @@ class MemberImporter(FromCOREPOSAPI, corepos_importing.model.MemberImporter):
             if withdrew == datetime.date(1900, 1, 1):
                 withdrew = None
 
-        typeno = int(member['customerTypeID'])
+        typeno = int(member['customerTypeID'] or 0)
         memtype = self.get_membership_type_by_number(typeno)
         if not memtype:
-            log.warning("unknown customerTypeID (membership_type_number) %s for: %s",
+            log.warning("unknown customerTypeID (membership_type_number) '%s' for: %s",
                         member['customerTypeID'], member)
             typeno = None