I haven't seen one since the 90's outside of the opposed Briggs twin with carb mounted pumpYep, i've never seen a rebuild kit for one.
yes, I have two dismantled and I'm trying to figure out how I can rebuild them. the only moving part is the rubber diaphragm and then there are two cheap thin plastic one-way valves. there must be a way...Beside if you got some time those hockey pucks can got for under $7 including shipping if you want to support the Chinese.