I believe you are referring to this as the “snubber” on the latch”
It’s metal, likely steal. I suspect it is pressed in. Was it removed or did it
just fall out? I don’t think you’ll be able to solve that mystery or why
the other parts have come up missing. Being taken apart and not being
able to get it back together (when there wasn’t anything wrong with it
in the first place) would be my guess. The Penn’s had a complete timer
for sale on eBay recently but I see it has been sold. You’ll probably have
to buy a complete timer to get the parts you need unless you’re really
lucky. I don’t have that kind of luck.
Tubs.
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.