I have a real early Fordson that needs to have the fuel tank cleaned and re-sealed. It was sealed at one time but now it's starting to come loose. It is the main tank not the little gas starting tank.
I've used this product on 4 gas tanks so far (3 motorcycle and 1 T). (assuming its a rust/pinhole problem - not a structural one)
Results have been excellent in all cases. One of the motorcycle tanks had some rather large pinholes. Sealed that one 6 years ago and still fine.