Good petrolhead movie that.
Have they even bothered to provide you with the information as to where it has been serviced over that period? Surely this would only require a quick call to the previous owner and they would then be able to tell you.
I'd probably want a drive of it if I were you to, so at least then you can say, ok, this was the right decision or not. Sometimes worth moving a bit on budget to get what you want, obviously without being seen off.