Thanks all, I bought the bike from a young guy in San Francisco, he'd bought it a year previously from the LA area. It was advertised with 8k miles but I'm not so sure that's genuine. The grips and footpeg rubbers look pretty good though. As far as I can see the bike is (was) all original (apart from an ignition relocation)
So far I've replaced the control levers, the stiffest clutch cable I've ever seen, a starter solenoid, tires (10 years old and cracking).
Issues I'd like to address:
Front Brake squealing
Tail light and low beam not working (bulbs are ok)
Ignition bracket was relocated to the fork clamps but I'll probably move it back to the stock position
Head gasket(s) leaking, so I've to clean up the head and see what I can do without a rebuild
Exhaust could do with a cleaning and touch up with some chrome paint maybe
Front brake cable replace, (are stock-like cables still available ?)
Front brake switch doesn't seem to work
The sidepanels are all there including decals, but some cracks have formed and the previous jbweld repair needs fixing.
Powder coat a few badly rusted brackets, and touch up any rust on the frame. I'm itching todo a full restore but the patina of age has grown on me . . . so to speak.
Amm that's all I have until I start taking off the various parts and see what I find. Its super fun learning about the technology from back then and how modern bikes differ (or doesn't in many cases).