The very first L72 COPO Camaro 427 engines were assembled January 3, 1969. That's a common date, along with January 4th. Those engine dates are found in the earliest COPOs, built starting January 15, 1969 at the Norwood, Ohio plant.
The vehicle in question has an engine stamped T1120MN. That's 44 days prior to the earliest known L72 engines. It is also the only one known with that date. The car was built December 5, 1968, 41 days prior to the first COPO Camaros out of Norwood. The ducted hood that was standard equipment on all COPO Camaros did not exist in production at that time.
You be the judge.
Here's another thread.
http://www.camaros.org/forum/index.php?topic=14502.0