Yes, I'm not surprised. Someone else did a similar thing to a Pac cab using goof off (2). I was really paranoid, so I did a lot of research, and narrowed it down to heat gun or goof off. Went for the heat gun and then stripped a small section. It worked, but I gouged the artwork a few times and it also left black streaks from melted latex paint, so I put it on hold until I tried Goof Off. I tried that stuff for all of about 5 seconds! Smear, smear, smear! I knew instantly there was no way I could get it more precisely using any kind of chemical like that. I still bet there is SOME kind of chemical out there, that if applied properly, will make the latex just disintegrate enough to be scraped right off, but I've yet to find it. So, I went to town with the heat gun. It's too bad it took a whole 1 side of my cab to teach me the proper method (even after reading how other people did it.)
Objectively, when used properly the heat gun is pretty damn amazing. If you're careful and do it right, top latex just falls right off leaving pristine oil-based art underneath. There's SO many things you have to keep straight all at once though. You have to wipe off the scraper after EVERY single pass (I eventually started wiping the scraper on my pants, very quick!

). You have to periodically cool down the scraper since it gets flaming hot and hurts the artwork on its own (bucket of cold water). Forget about a plastic one! (would be nice though...) You have to scrape at the right angle (cornerwise down worked best for me) so the paint falls in front of your scraping rather than getting in the way. You have to know just the right amount of heat to apply to loosen all of the latex without burning the artwork or softening it too much so you might scrape it away. You have to hold the scraper at as low an angle as you can to the surface, to minimize gouging. You have to use just the right amount of force (solid, yet not forceful) to get all of the latex but not gouge the artwork. There's probably a ton more tips I could give, and even I don't do a perfect job yet. Someone did a Joust this way with almost no artwork damage at all. They must have been damn masters at it, because even after reading their tips it was NOT as easy as they made it look.
Well, anyway, glad you restored a Pac-cab anyway. New artwork isn't as satisfying as rescuing the original, but at least you tried.
