OK, so here's the update:
Gas tank is leaking in a new place for sure. The good news is the patch stuff I bought seems to be working. So, I need to drain the tank, strip the paint and bondo out some more and find the other leak. I also might be getting a second tank just in case.
Fuel petcock is all messed up. I think I'm going to just get a new one. Apparently these bikes are notorious for having a fouled-up 'c0ck.
Real GS500 gauges are in the mail! The 1980's CB gauges I've been running will be seen on eBay shortly. I just need to find out how to run the mileage up on the new gauges to match all my paperwork. I think an electric motor and little gear will do the trick (it worked for the GL back in the day).
Also, I recently discovered an exhaust leak. Seems to go away once the bike warms up which is a tell-tale sign of cracked exhaust gaskets. I'll take the pipes off and paint them and replace the gaskets maybe next week.
; )
