Paul,
The car would have been built at the end of Feb, beginning of March. So that engine date looks fine.
Problem with finding the car is
1 - it's not around anymore
2 - it's not registered. Someone looking for my Z would not find it via the DMV because I've never registered it. So the car could just be sitting in a garage somewhere in pieces.
I'd say the chance of finding it are low, but we have reunited several (blocks, POP's, etc) with the original cars over the years, so the chances are not zero.
Thanks for the pics!