Goes to show that you must be in a warm & less-rusty area. I don't even see any original Rabbits here anymore, unless they are in the garden eating. ;-)
Hmmm but I think from the factory the exhaust nuts are special. Maybe that engine had been worked on before or it is one of the new Rabbits. Are you pulling our legs? I don't think that any of the original Rabbits used allen-head nuts or bolts for the exhaust studs. I could be wrong though.