Right on, Svr and San Rensho - thanks for the recommendations. I may order some pieces from loose screws. No idea that the plunger piece was leather until I looked at it carefully after taking the pump apart. It'll be good to use it again and keep the cheap Nashbar pump on schraeder setting to use with my commuting bike.

Edit: the leather plunger piece has re-expanded from sitting inside the greasy pump barrel for a couple of years when the pump has been in my attic. So I don't need to replace it.