14 FF swap/cucv-what year could it be?

[SunSoaked]

In swapping a 14ff rear axle (from a cucv) into my 85 K20, I decided to open it up and do a good inspection first. All looks good, except, I cannot find a spindle nut socket at any store in town. This nut has 6 half round notches on its outside diameter and several 1/4 inch keyways on its inner diameter. The keyways are retained with a flat circular spring clip that locates on the hub spindle threads. There is an inner and an outer bearing and only an inner seal.

Any idea what year this might have come from? Iv'e read there is a "new" and an "old" style 14FF that changed around 85. I'm not sure I even need this socket; the axle was well maintained and came apart easily. I was just looking to seat the bearings before backing the nut off to the first keyway that lined up.

Appreciate the help.
Mike