You've still got that pesky & in the local part number field.
Going back to your original post. No one was trying to talk you out of including customers in the application. They point was really, how are customers and vendors different? Could a customer be a vendor? Even if a customer would "never" be a vendor, you still might consider using a single table for "entities" rather than separate vendor and customer tables. You could just use them interchangeable, pick compA as a vendor in one case and compA as the customer in a different case or, you can add a flag to the entity table and check it when the company can be a vendor. The assumption is that every row could be a customer but only some can be vendors and you would use that flag to restrict the entities in the vendor combobox on the form. By combining vendors and customers, you would also combine the reps tables. A rep is either associated with a vendor or a customer depending on the foreign key in the rep record. This simplifies the app and reduces the number of individual objects you need to create and maintain.