I would look for service history cam belt change, oil check is it sludgy, listen to the engine does it rattle or is it smooth, does it feel smooth on accelartion, are the gear changes easy, does the clutch pull properly on hills, do the rest of the electrics work, how long is the MOT, does the suppension knock whenm going over speed bumps, rev the car up on a cold start check for black smoke or strong smell of petrol. Look at the rear exhause box is it majorly rusty. The price sounds good for a 51 147 with 66k on the clock thats an average private sale price and not really that cheap but not dear either a dealer would want 2k +.
Check the tyre tread is ther any does the car pull to one side on brakeing or driving and are there any warning lights comeing on on the dash.
There are a few London independantsts for servicing repairs try Proietti ( I thats the right spelling) they are in London and ask them the cost of of this repair.