Check odometer for operation, not uncommon to have the odometer fail, so the mileage may not be correct, if the odometer doesn't work .
Fork seals for leakage .
Original OEM rubber brake line(s), long past time they were replaced if they are original .
Check brake master cylinder for leakage, not uncommon to get corrosion and pitting on the cylinder bore .
Check steering head bearings for smoothness .
Check inside of fuel tank for rust, pretty common to find rust, if the bike has sat for an extended period of time .
Engine oil on the shelf area under the transmission, rear main seal leakage is common .
Neutral switch for leakage and operation .
If you can, remove the filler plug from the transmission and check for a milky brown color oil, water gets by the speedometer cable boot, where the cable goes into the transmission .
Original Boge shocks should be replaced, they were not very good when new .
Gear oil on the rear wheel /tire, leaky final drive seal .
Open the seat and remove the fuel tank if you can and check for the condition of the wiring, or any previous owner ' modifications ' !!!
Fairly common to have the forward ignition coil mounting bracket crack on the ' first ' generation R65's, it is also the main ground point for the bikes electrical system, causes all kinds of odd electrical issues .
Ignition wires look like they may be the original OEM wires, time to replace then as well .
Check the 4 digit date of manufacture on the tire sidewall, may have old hard rubber on those tires .
Check the mufflers for bulging, cracks and rust through at the rear weld area where the muffler starts to taper .
By the way, very clean looking bike, with current registration, so may not have been sitting around for any length of time .