Vehicle fumes

Hey guys... Looking for some help on fumes.... The car when in the garage has fuel fumes. Found that the gas cap had no gasket (fixed) and the PCV valve was not secure on valve cover. (fixed) Filled the tank. Still have fumes but not as bad now. New gas tank, boot etc. No drips that I can see and find. Can the canister (charcoal) go bad? Also on this car 71 Mustang Base 302 on the valve covers there are two connector holes. The driver side front for PCV valve and the other passenger side rear open with a rubber grommet? Also I have an open Chrome breather vs the factory one. Any ideas?

Tos; Thank You... So would the fix be to rebuild the carb? Or can this be something that is Ok even through the fume odor is there? I am just concerned that when winter comes and the garage being heated I'd have a bomb sitting there. Thanks

Tos and members. I'll try the Seafoam. I also checked the canister and when I tried to blow thru the line to the tank did not see or hear any air. Also blew in the canister and I did get air from one connector to the other out but the charcoal I guess could still be bad in the can right? The tank is new and the air vent connector is on top of the tank so I would have to drop the tank to check it. What a crazy situation.