Sounds OK, all the major works been done, money been spent on it, think the only way is to arrange a test drive and go from there.
Money wise its all down to how its been looked after and how it goes, open to offers, so go in low and come up.
Seeing head gasket has been done run it till it gets hot, offer to put a £5 worth of fuel in if he says its low on fuel. Or take a can in your car, just normal stuff like looking in the water filler bottle, oil cap, dipstick.
Best of luck with it, if you go for it.
