It's looks like it's in really nice shape under that dust.
I'd use a POR kit to clean and coat the inside of the tank.
I wouldn't assume the carbs need to be rebuilt. I'd get some fuel flowing through them - i.e. ride it for a while - even if it's running a bit rough - before rebuilding carbs.
There's a vacuum actuated fuel shut off built into the fuel tap. I think they're pretty bulletproof but if you trouble getting fuel from the tank to the carbs - check the tap first.
Brakes are easy to rebuild - probably don't need anything but a complete disassemble, cleaning (particularly the seal groves - you can use a dreamel with wire wheel for that) and reassemble. If you do need new seals (I bet you won't) I think they're still available as the Ascot caliper was used on a bunch of other Honda bikes.
Check and adjust (if necessary) the valve clearance. Easy to do.
Hard to tell the year from the pictures as there was a black model one year and a very dark blue (which can look black) model the other year . The year will be on the steering neck ID plate/sticker.
It'll probably burn some oil as the valve seals from that vintage tend to get either hard or soft and leak a bit. Unfortunately you have to pull the motor to get at the seals (but it should be possible to do without removing the head) - but I wouldn't bother until the time you have to have the engine out of the frame for some other reason (which may be never
- just be mindful of when you need to add some oil.
If you don't buy it, let me know, I'm interested (depending on where it is).
