i've always been able to get that puddy off with a reg razor blade...

im sure i read that you have the car ready for primer already but anyways...tiger-hair is a lot stronger than bondo, has a high content of fiberglass strands in it...if mixed properly you could hit it with a hammer and barely get a nudge in it, as far as bondo...crack like no tommorrow, if not chip a peice off.
jeff