None of these mods are very difficult. The vent can be cut out of your old tank & welded to the new. Some later models just punch a hole in the top & use a grommet & plastic fitting. I will look to see if I can get this at an auto store. The Mustang tank connects to the filler pipe with a hose. It is the same diameter as the Maverick filler pipe so that hook up will be easy.
The benifits are that you can buy a new tank & sending unit. But the biggest plus is you now have tons of room to run a 3" dual exhaust if you like. Even 4" pipe will clear easily.
I'm going to order a new gas tank kit from CJ Poney parts. New tank, sending unit, connection hose, gaskests & hardware is only $128. Or, if you perfer a tank with a drain, $142. I'll keep you informed of the progress