Beo and C-dan recommended PB back in the day over at SOR. I bought a can and was amazed. A buddy of mine with a '67 Stang keeps trying all this new stuff that crystallizes the rust and junk but I stick with my PB.
Junk that was STR that wrote the recipe for that wicked homebrew. Some conction of kerosene, gas and some other stuff. Sounded pretty potent. If you want it I still have his email somewhere. He also has a wicked Pinzgauer.
A lotta heat and some PB and there ain't nothin that won't come loose... um 'cept that nasty siezed TRE bizatch two days ago...