Looking forward to your thread. 
Not surprising to be honest, given the age of the bike and our rather damp weather (80% humidity up here today!). You'll need to give it a detailed inspection, using a screwdriver or some such to take off the flakey rusty parts and don't be afraid to prod the rotted parts to assess how far it's gone, why? It's your safety I'm thinking of. If it aint too bad, a light refurb, repaint may do, otherwise source a good quality replacement (not easy for the Gen1's). Post up some pics. Mine is a '97 and it's rotting from the inside out, nothing I can do about it. Been an advisory on the MOT the past two years, so it's gonna fail at some point I reckon.This thread is a bit about me and a lot about my EX-500 which I've had for about 5 years and is so good I've decided to nut and bolt resto because I think it deserves it.
I'll do my best to add pictures and report what I find.
I've already found that the centre section of the swingarm is like tin foil, it had corroded from the inside to out. As you look at it on the bike it looks normal. I tapped on it with a screwdriver and it went straight through scary 🥶👻