Here we go again.
1967, 68 and 69 called out: 352361-S100 8-18X1/2RND/WSHR 13/32, XREC, TPG, SST - SCREW, ROUND/WASHER, PHLPS, TPG
Ref Assembly manuals: N7-8940, N8-8940, N9-940, the screw is shown on page 162 of AMK Ford Fasteners.
1970 called out 42366-S40 8-18X1/2HH, REC, FLNG 11/32, TPG, 1/4HEX, BLUNT TIP - SCREW, HEX, REC, FLNG, TPG, BLUNT
Ref Assembly manual N0-940, the screw is shown on page 151 of AMK Ford Fasteners.
What is show in any MPC is a fastener that is more common in a dealers service inventory. It may or may not be what was originally installed, in many cases it is NOT.
Pictures show what the assembly line may have used (elapsed time is a factor), or what was used in a paint shop.
Jim