Boy thanks for this. I wish we could get more guys who "do stuff" to weigh in. Lee Robinson is always selling "removed sheet metal" he seems like a prime candidate I have what amounts to zero bodywork knowledge
I have several spot weld cutters. the little center left after is annoying but, I like how quick they cut and they make it pretty easy to see when your through the panel.
we use some old chisels to split the panel. no where near as flexible as yours though.