[yorkie_chris]

If I was getting it ready for serious use I would;

Remove carbs, soak in petrol.
Pull plugs, teaspoon of oil down each bore.
Flush the tank.
Strip and rebuild: monoshock linkages, head bearings, wheel bearings, calipers, forks.
Drop the engine oil and coolant.
Before refilling engine oil, remove the cam cover, dump a pint or so of cheapo oil over the working parts. Might as well check the valve clearances while you're in there. (turn it over by hand at this point)
Then refill the engine with oil and coolant, refit the carbs, fresh plugs etc.
Renew the air filter
Very carefully inspect the tyres, no point having a painstakingly rescued chassis on cracked and worn out rubber.

Of course this may be OTT if it is just destined to go out 3 times before being sold in favour of something else...