Looking for a filler cap for the pump on the left below. The filler neck has two bumps on the outside so the cap has twist slots rather than ears.

What is the factory designation of this pump i.e. 1.02, 1.06, etc? Most sources list them by maker i.e. Federal, TRW, etc.

If memory serves, those used a stamped/drawn cap that was knurled, right ?
Had a tiny vent hole in the top ?
I think Dad's '66 Sport Fury had that, or maybe it was the '64 Savoy.

My 64 300 had one of those style caps.

I believe it's part number 2127284.

https://www.ebay.com/p/1258201577

^^^ Yup, and plated like that, not painted, is what I recall.

You need to look at shaft to determine specific pump size along with can dia and possibly the casting markers on pump if original type. The Early pumps were Thompson. A .96L with solid shaft 4 5/8" dia can, and the 1.20L with Hex hole shaft and 5 1/8" dia can.