It looks like a super buy.
Further to my last post, advising you to clean the sludge trap, can I suggest removing the oil tank completely from the bike and cleaning it out with petrol and a bottle brush or similar. I think you will find a black gunge at the bottom which is best removed at this stage. Having cleaned tank and sludge trap, refill with new oil and run for about 500 miles. Then take the tank off again, clean it out again and do the same with the sludge trap. If it hasn't run since 1960, the old oil would not contain detergents so the engine and oil tank will have the black gunge inside which comes from combustion and generally running the engine. Modern oils contain detergents which will wash the old deposits off the insides of the engine and put them in your sludge trap. Being a single, this is easily cleaned through the sump plate hole. It may be worthwhile taking off the timing cover, removing the oil pump and generally cleaning it and checking its function. Put oil into the oil tank before you tighten the pump back up so that you see clean oil coming out from behind the pump before you finally tighten it up.
When you have the back wheel out to fit new tyres (Avon AM26 are my choice) check each side of the plunger assembly for movement. If the previous owner wasn't religious about greasing the bushes you will find they are worn. Handling is much improved with new bushes but do grease them - religiously.
36 4G, 37 VH, 53 ex ISDT KHA (project), 54 KH(A), Healey 1000/4 (project)
Former Machine Registrar & Archivist, General Secretary and Single Spares Organiser (over a 25 year period).
Now Archivist once more - but not Machine Registrar.