Since it is original engine with factory VIN stramp , and the cylinder head casting date shows to be April 13 1971.
Lets us know from that the car was built after that date by at least a week or two minimum. So late'ish April.
That would make this the first invoice , and the only invoice on this car.
On May 1st
Very cool hard loaded convertible with some neat born with history , plus its going to be a low production number .
Great Find and Congrats to you