went to buy parts at a local auto store recently ( CV Boots ) and told they could not supply ( not stocked ) even when we provided make, model, year and OEM part no. Went back with an old aftermarket ( their "home " brand ) box showing part numbers and they found them on the shelf.
Apparently with the "new" on line parts systems, if the stock is entered / inventoried without an OEM part number, it can't be located as the systems are not set up to cross reference by make and model anymore.
God forbid that the parts person might actually recognise the old part you have in your hand, the vehicle it came off, and know what to look for in their shelves ( ! ) ....