120K , £850.00, sorry it is not just about the engine , forks are going to be pitted , swing arm likely corroding from inside to out , wheels likely will have stress cracks not visable to the eye, I would not take that as a gift you are only going to buy a heap of trouble for yourself. As regards him saying he will put it through an MOT, so what !! brake pipes will be needing replacing. Walk away mate save yourself the grief.
Lew