I needed the heater vacuum switch for my 70. It was priced 75 on eBay. One guy had one said nos. You could see the screw marks. Got it at the Buick farm 35.
I had a Base ('69 Chevelle 396) for one of those air filters once. (AC Delco 212) No Lid. Had people falling over each other to buy it for $200. should have put it on Ebay as an auction, was already done with them at that point.