The air chisel is a very good idea, I still have a old CP9 with some tin weevil chisels thats ideal peeling spot welded tin off things, although powerful struggles at a 1/8 inch tinwork will throttle back and split a pencil line in thinner tin. With things on a taper a straight gentle pull may not work. A friend had a Alvis car wheel hub well stuck, not only did they have the very strong standard puller but also a legged hydraulic one over the top to no avail. With the standard puller pulled up tight, flash heat and the burrrrrup of the air chisel was off with no damage, I have seen quite a few things that were just forced to be shifted like time as often leave over night under load and carful treatment would have worked.
