This caught my eye as it was hardware related, but it is not documented in the "1969 Mustang Body Assembly Manual" (several pages are missing). The notes in my copy (paper copies are good for that stuff, making notes) refer to the 1970 Mustang Body Assembly Manual, some items are the same, others are different. The hood pin is different. Mustangs in 1969 used a pin/cable retainer, in 1970, a "twist lock" was used.
That's the preamble, here's the meat.
The 1970 Mustang Body Assembly Manual (AM0031) page 17 (N0-105-1) has a revision that shows the "proposed" use of the 1969 pin/cable type but it is lined out, aka, revised - but it is still there.
I'll scan and post that page later.
Jim