On the 2100S sheet I have from November 1953, the parts list shows part 61-431 Upper Pump Spring (outer) and 61-432 Upper Pump Spring (inner), in addition to 61-510 Pump Diaphragm Spring, which should be the big lower spring. This is the only 2100S sheet I have, so I can't speak on design changes/updates.
Maybe Carbking will chime in at some point with an expert opinion.
Last edited by EchoBravoSierra; 09/26/2023 7:57 PM.
