Thanks for the warnings all. I had done a section of the bow before you brought me to my senses. Hopefully the rivets below look OK to you all. For the rest, you were right that things improved with a warm-up. Still never really peeled, but softened up to where a scotch brite got it up easily.
Any way, the underside is now fully stripped.
Next up: the trailer! It's now fully broken down. My plan is to soak pieces in vinegar (using WOG's ketchup trick for the big parts), scrub, apply Rust Converter, prime and paint. I'm also going to repaint a rusty WheelHorse tractor, so the trailer will be glossy red too.