actually Dave light does have mass
Trevor.. I really really wouldn't be happy unless I've seen the valve guides were intact - any contact at all, even if it wasn't enough to bend a valve, could've put a crack through one - I'd rather not have that sword above my bed
there is also a very slight amount of play in the valve stem/guide - enough maybe to allow the valve to seal ok in one position, but rotate it a little and you could have problems.
don't chance it imo.