Need info on 41 Commander zinc sizes.

Fellow Commandeers,

I am taking my 41 out of the water and will replace zincs. My shafts are 1 1/2" so I've got that covered but I don't know the size/shape of the rudder zincs, or any other hull mounted zincs the boat can have. I've always had my mechanic do the zincs and he just died, so I don't really know. Would like to have the replacements ready as soon as the boat comes out of the water. Boat is fully original from 1979, so I'm certain rudders have not been replaced.