It has been stored out of the weather the whole time. I think I like the idea of taking it down to filler, I do know that it would be best to remove it all down to bare metal but there is grey epoxy under the primer (no idea what kind) that seems to be stuck to the metal pretty good and somebody did a lot of nice filler work, so I don't want to jack that up. Would it be Ok to use a DA with 80 grit on the more flat areas? Most of the car has big ol' curves and won't be fun to block! I have read lots of good info about SPI epoxy and think that's what I want to use to seal, is this a good application for that product?