Well, decided to tidy up the bike a bit so started stripping it down. In 2 days my housemate and I have stripped it to bits in the shed.
Plan is to blast and paint the frame,
send bodywork off for spray,
new h'light
new bar-end mirrors from the states
tidy up the wiring,
new clutch cable and head gasket
service (plugs, filters and all fluids)
... and hopefully put it back together within the next couple of weeks and get it to start up again....