In 1972, Ford replaced the 1961/66 in cab gas tanks with the later 1967/72 tank. This newer tank has a 19.5 gallon capacity, and uses the original sending unit. Only one fitting is different.

So look for any 1967/72 tank in a wrecking yard. Get the fitting also, its right at the tank.

New radiators can be bought from parts houses, it may also be possible to have your old radiator re-cored. Transmission parts are available, what's wrong with yours, or don't you have one. Two different 3 speed transmissions (Ford & Warner) were used on the 223 engines in the 1960's. You'll want to get the correct one.