poor guy, he would have been told by some idiot in a garage that it's pulling decent power and clearly doesn't know for sure.
i love the switch for extra boost too, worse than a bleed valve, EBC is where it's at.

22psi could be pulling over 200bhp, i know of a lad using a carb turbo setup and 25psi and pulled 240(something, can't remember exact figure)bhp, they reckoned it's go more if it wasn't on a carb as it was restricting too much.

who knows, it isn't a bad car, just needs some attention and for that i'd offer £1500 if it is in good nick.