Carter 1 barrel carb leak in 64 valiant any ideas??

I just picked up a 64 plymouth valiant. It has a 1 barrel carter bbs carb and push button auto. The leak is at the top accelerator plunger (bowl vent valve). Is there a gasket or something missing? Rebuilt carb, but not by me bought it this way? Can any slant six 1 barrel work with the push button tranny? New to the push button and not sure if the linkages will work? Thanks