best speak to a pro bodywork finisher, i know you can tack weld it all the way to try to prevent kinks,but a bit of a big area to fuck up if not rite!
and i dont know if you can just go ahead and fill in the remainders with hot weld after that.


spose you could go down
the scrappy and av a word with the owner to experiment on a pre crusher with your mig,just to try.