Have you talked to a PDR (paintless dent repair) shop/guy?

You'd be amazed at the different tools/picks that they have and and can get in tough to reach places to work out a dent.
It's thinker metal than the new stuff, but they can usually straighten it pretty good or at least get it close enough to where it doesn't need much filler to make it straight.

If the metal is rust free and solid it would be a shame to cut and weld it.