Overall length of my '69 tail panel in a straight line is 52". With the tape measure following the slight V shape, the overall length is about 52-1/8". My car is in paint, so I can't measure the trunk lid holes.

The centers of fastener slots on the tail panel from driver side to passenger side with tape measure following the slight V shape:

Top row - 2-5/8", 9, 17-1/2, 26-1/2, 34-9/16, 43-1/16, 49-1/2.

Bottom row - 1-1/16", 9-1/16, 17-19/32, 26-5/8, 34-5/8, 43-1/8, 51-1/8.

I don't have the 14 fasteners handy, but they are a reveal retainer #10-24 x 7/16" with olive drab or soup green enamel finish or maybe green zinc chromate (same as used on the interiors of WWII aircraft). I believe these can be shifted left or right in the tail panel slots about 1/16". Half the tail panel nuts on one side of my car were nylon lock nuts, without any mastic, and the other side of the car had stamped nuts filled with mastic. The bottom of my trunk lid was badly rusted from water entry through the tail panel holes. For a water tight seal, mastic filled stamped nuts should be used on the backside of the trunk lid, and probably some caulk on the frontside of the hidden trunk lid holes. I plan to water test and inspect for leaks. And never allow the car to be rained on again.