I am trying to figure out what type of gas cap fits on my Barth. I am getting strong whiffs of gas, but there seems to be no leak anywhere. The old gas cap has a worn out seal. If anyone has a good idea as to what type of cap I should replace it with, please let me know.

Imasse , Why not just replace the seal on the gas cap ? My gas cap on the barth, has a rubber o-ring , that can be replaced i would think .
Bob

Just replaced the fuel tank on my '73 Twenty Five.
It wasn't leaking that I could see, but I was replacing the sending unit. When we got the tank out, it was rusted through several places in the top. The tank was flat on top, kind of dished down, and probably had collected salt (43 years in Michigan) and moisture over the years. Needless to say, this is a very dangerous condition.

inspect all fuel sending & return hoses thoroughly. you may have to drop the tank. It was not that difficult. Tere dropped both of ours, had sending units refurbed, replaced all hoses with marine grade hosing thanks to Rusty's suggestion. if they have never been replaced they are cracked & dry rotted. that happened to us on our '85 regency aka "old blue". kept smelling gas when fueling up at gas station.