Is there a number one source for new parts for old vehicles?

[bucolic_frolic]

3. Availability is sporadic on old parts

The parts most frequently replaced can get out of stock. After about 25 years they're all trying to liquidate their supplies because the parts aren't moving. Then at 30 they sellout to firms that hold more permanent inventory and the price goes way up. These are general rules. Some parts will never be found again. But I would try Rockauto.com as a first source. They go way back - as to how many parts there are for 1927 - who knows. They sure won't have every part. There are others, but there's also been consolidation in parts suppliers. Those from 20 years ago got bought out. Tire suppliers for example, most of the early seller websites are defunct now, they combined with the winners.