Seeing that you have nothing to lose, remove the plugs and turn the engine over by hand on the crank pulley. The camshaft will stay in position, then see if you feel any contact between valves and pistons. You can also shine a powerfull torch down the bores onto the top of the pistons. If there was any damage there, you will defiately see it. Also, take the cam cover off and turn the camshaft over by hand and watch the tappets. If one or more of them stay put when they should be rising towards the dwell of the cam lobe, then the valve stem is bent.
As Horney has already mentioned though, for the sake of 30 quid, you could just try your luck. It wouldn't be a waste as obviously, if you were to replace the engine, you would replace these items anyway.
I though these were clearance engines!
