There are 6 screws that are visible on the last panel, the fixed one, on a 66 Fastback. Four hold the panel to the body, the two rear most, 54511-S13, hold the bumper cup (called catch) and the panel, the front of the bumper cup is held by short screws, 54505-S13.
- the chrome oblong escutcheon. do the screws have washers?
The front of the panel has a cup washer, 34970-S, used with the screws, 52979-S13.
amk sent 4 machine screws and two black sheetmetal screws. where do the black screws go?
I believe those may be the screws, 52720-S2, holding the retainer bracket on the underside of the rear panel.
the assembly manual is light on details.
You should spend a few minutes in this Forum's Library under top Mustang Hardware Spreadsheets 64-66. You will fing two spreadsheets, one by application, the other by part number. Both have descriptions of hardware used, with referenced sources.
Here's a start. If you can ask questions referencing part numbers that should help us all from getting off track
Your drawing is from the service manual and, as such in many instances, uses replacement parts and hardware, not factory original that are shown in the assembly manuals. Yes, there are differences in plants, date of assembly and parts availability, many of which are documented on this forum.
Jim
