Finally had a bit of time tonight. Dug this guy out, no manual online even though some forums have pointed to one. Probably lost in the depths of the interweb or deleted lol.
I ripped out over a dozen screws, pretty much everything I could get my hands and a screwdriver on. Bottom plate off, springs and chain/slide off, spring anchor off. plate beneath bottom plate off, self timer off, lens mount off, and screws under the lens mount out... and I got stuck. One screw was rusted in much more than the others, I ended up stripping it. Tried breaking the bond with naphtha, rubber band in between screwdriver, sharper screw drivers, gouging out a deeper slot, even purpose made screw extractors from moody tools. All failed and I couldn't get deeper than that.
Was kinda pissed and sweating at this point, so I decided to drown the bottom half of the camera with a few big squirts of naphtha and work the slow speeds. Working the shutter and wiping whatever gunk leaked out. Did it a few times, and it started to work really well. I did a full wipe down of all surfaces, it was really dirty. The camera basically has a hole in the bottom that allows grime in, the wind on movement also creates tiny bits of metal shavings. I applied graphite powder to all the contact areas and worked it in with a bit more naphtha.
Seems to have worked out well, 1 second is a little off, but all other speeds work well now, even the high speeds. I also fixed the weird trigger wind on extra 2nd pull. The previous person who took it apart failed to double check the position of the cog when reattaching the trigger chain. All good for now, will check tomorrow and hopefully the naphtha bath fix doesn't evaporate off and have the speeds slow again.