So looking at the strap very closely, what I got is DEP C4ZE 8005 A1 4GD. It does have squared straps, but the "x's" aren't visible in the strap holes... Looks like it was re-welded/spot welded there.
Again, car is VIN and door plate verified 64-1/2 convertible Dearborn 260 V8, 2v, 3-spd manual, production date July 20, 1964, but no factory air.
Tried to get a pic of the strap, but kinda tight in there!
Thanks
~Ric G