To strip or not. to strip...

I second the contour tool. It came out a few years ago when I was stripping a car that some idiot covered in 1/8-3/8" of bondo...for no reason...on top of several layers of paint. I almost purchased the contour tool but Eastwood did not have the abrasive heads for it as they were on back order. I tried chemical stripper-several brands, including aircraft stripper and the new stuff is about as useful as non-stick glue. It is so safe, it doesn't even harm the paint your are trying to remove!

But your question was to strip or not. I say strip it down to bare metal and use a DTM epoxy primer over the bare metal. DTM stands for "direct to metal". Follow all the instructions to a tee and be sure to prime it as soon as you can, even if it means doing a section at a time. Flash rust will occur within minutes of bare metal being exposed, so you want to protect it from that. Again read the instructions for what you are using but they may suggest an etching solution or the primer may be self etching, depending on what you buy. Also, keeping the surface free of silicone and oils is very important. BEFORE you strip it mechanically, wash it with a soapy water followed by a very good wipe down of wax and grease remover, intended for auto body work. Otherwise you may grind the silicones or whatever into the metal and you may get fisheyes in the primer.