I'd say it could be worth a look, with the proviso that it may well need a lot of work doing to make it a good long-term prospect. If there's no service history, you'd have to assume that no service work has been done. (Why would a good owner not keep service history)? This adds at least £400-500 to the cost of the car immediately because you'd want to get the cam belt service done immediately, as the previous poster points out. Having said that, this is a lot of car for the money and even with a service factored in, it's still a good price.
HOWEVER, this assumes that there is nothing else wrong with the car. If your friend is not one for spending lots of money and lavishing attention on his car this may not be ideal because of the uncertainty over its history. A dealer can tell you all they like about a car but unless it's there in black and white, they might as well be telling you that bears don't **** in the woods. That beautiful exterior may hide a multitude of costly niggles/MOT failures/bank account emptying issues that make it not worth the uncertainty.
Within a month of buying my GTV, I spent about a grand, and that wasn't even for servicing (mostly suspension). At the time it was a similar age to that of this one but 30,000 less miles on the clock! I know this car may be completely different and I don't mean to put a downer on this, but I would like your friend to go into this with his eyes open.