ah ok, can't help on the question other than to say a VIN stamp was a requirement by law/regulation, not sure when that went into effect, late 60's I think.
All Vipers had the VIN stamped in the trans and engine.
When I worked at Chrysler my department authorized all VIper engine and trans replacements and repairs.
Some owners wanted their original engine or transmission repaired instead of a new one so we accommodated them through a repair service.
Arrow Racing did the engine repairs. I forgot who did the trans repairs.