The part is likely metric.

Calling a dealer for part numbers is exceedingly bad form, they are busy enough with paying customers. If someone was wasting your time at your job, how long would you tolerate that?

As for a low cost part costing $ across the counter, There is a certain expense floor incurred to even deliver an empty plastic bag, add in the cost of sourcing the part, storing a slow moving part ( if it sells at all ) for 26 years and it is going to be more $ than if you bought a box from the manufacturer. You are likely the only person that has ever needed this part in the past 26 years.

Find this clip on the open market, buy 1,000, generate an E bay listing and see what happens.