Ahhh... I miss '80s hairstyles.

Anyway, I've not yet heard a good way to get paint off of other paint without damaging the important stuff. I have done it before, however, and it looks like you're in better shape than I was. Years ago, I bought a Super Course Mk II frame that, reverse-coincidentally, was originally red and had been entirely spraypainted pink. I was able to scrape the spraypaint off very (very!) carefully with the dull side of a knife blade. It took absolutely forever and I can't really say that I'd recommend it, but it did work and I didn't do too much damage to the original paint. In fact, I even managed to preserve most of the original decals. So if you can't come up with a better option, it can be done. And the great thing about yours is that when you get about halfway done and start questioning your existance you can always quit without the frame looking any worse than it does now.