We have been told that the head gasket will be virtually impossible to remove without breaking the long bolts which hold it in place (it is the original part), making it impossible to fit a new one - therefore we should wait for it to go completely and then have a new engine.

Is this correct or is the mechanic trying it on a bit? Is it likely to break when removed - given that it is the original part - or is it worth a try?
Ta - Donna