My 1969 05A Norwood Camaro appears to have the 2nd design (with the four holes in the inner panel). The inner panel is stamped "T A10" in raised rib, to right of the jack instructions, and "A10" in a second spot along the middle bottom of the raised rib.
If I recall correctly, the T is the stamping plant, and stamping plant codes are typically H, K and T. Has it been determined which plants these codes stood for?
The “A10” stands for the 10th week of 1969 which would be the week of March 10th, correct?