PirateFins

A friend of mine has a '85 2wd stnd bed pickup with a 22r carb'd motor. He needs the Aux. Accel. Pump Diaphragm for the carb. Anyone know where (other than the dealer) we can get one from or if it can be repaired how to do it? I did a search on the web and couldn't find one listed for a '85 but did find one for a '81. Will that work? He doesn't want to buy a whole rebuild kit if it can be avoided.
Thanks