I'd have to check the stamping but think I may have it's brother w/ 775 G/Y Power-Cushion I pulled out of the trunk of an original '67 Cutlass?.
Here's what some Googling shows too...
14 x 6, 6-4 ¾ Disc brake, stamped steel - P/N 9791450 - stamped HB or HF near valvestem hole.
- Buick Special '68 w/disc brakes exc Rally wheel.
- Buick Special '69 std duty exc Mag wheel.
- Buick Special '70 std duty exc Mag wheel or space-saver wheel.
- Grand Prix '69 exc Rally wheel or space-saver spare.
- Olds F-85 '67-68 disc brake exc chrome Super Stock wheels.
- Olds F-85 '70 exc SW or Super Stock wheels.
- Tempest '67 exc Rally wheel or space-saver spare.
- Tempest '68-69 exc Rally wheel or space-saver spare.
~ Pete