[Farmall] Stop leak oil additive

[John Bailey]

When I rebuilt my 1950 Farmall Cub, other than replacing a busted piston and grinding the valves, I really didn't do any more rebuild work on the engine.
I now find that both front and rear main seals are leaking, not a lot, but just enough to leave a little spot of oil on the driveway. It's really not that big a deal 
as I never plan on working the tractor, just show it and ride it around the yard occasionally.

I have seen oil additives advertised that will supposedly recondition oil seals and possibly make the leaks stop. Has anybody had any experience with such
additives? Should I try one or just leave it alone?

Any advise would be appreciated.

John Bailey