Your truck has the factory box rails, so the "hooks" would be redundant on the sides.
The tie down hooks were both a Dealer and a Factory Option. Like the factory optioned mirrors, and radio antenna mast, they were not installed at the factory due to shipping issues. They were placed in a box on the seat and were installed at the dealer when delivered.
The "8" foot bed had 8 hooks. Three on each side, and two on the tailgate.
The "6" foot bed had 6 hooks. Two on each side, and two on the tailgate.
EDIT: ......................
That reproduction reflective piece is a great way to restore an otherwise good aluminum panel.
The reflective piece was not offered separate from Ford.
Truck: 1981 F-150 Explorer / Engine: 300-6 California MCU Feedback System / Trans: T-18 - 4 speed / 2.75 Ford Rear Axle Open Diff.