After trying phosphorc acid (or something that supposedly had phosphoric acid in it), all kinds of scrubbing techniques, and digging rags out of the tank due to failed scrubbing techniques, i finally decided to just sandblast the cursed thing. I know it's a bad deal to have sand in a gas tank, as it dissolves into the gas, but I was at my absolute wit's end. I used a combination of compressed air and shop-vac to clean out the sand, tomorrow I'm gonna rinse it with gas and I'll just use a fuel filter from now on. But the tank doesn't have the rust scale deposits on it anymore so hooray for the good guys! Oh, and I also bought a Biturbo pipe. Now all it needs is some Black Flag and Dead Kennedys stickers to complete the beautification end of things. Oh, and Fifteen stickers, too. Also, I just skipped using the Kreem i got for the tank, because the tank has to be removed to apply it, which means stripping it down to the frame, and the wiring is a nightmare just removing the forks. But I think it's ready to go soon. I can't wait till spring.
Struggling to find my way around doing things the right way always,