You can tell by the bare spots that, even though she has been treated badly, there’s some good quality metal there. Many lower end steel bikes rust like heck when the paint is chipped-off and exposed to the elements. I think the Japanese threw some extra-good elements into their metal mix. I’m going through the same thing with an old Miyata that has obviously been neglected for years. I’ve come to the conclusion that a bike is much more than its outer covering.
I think she is worth restoring. Powder coating would seem to be the best option if you want it to look good. It is normally a 100 buck job with old paint removal on the Left Coast. However, I might consider doing nothing more than a thorough cleaning and making the drivetrain and everything else as spiffy as I possibly could and throw my middle finger in the air at all who didn’t get it.