These nocks are plastic, but seem to be a different plastic as compared to other nocks, whether they be new or old. They're not well made. Very rough. The hole at the bottom of the nock is 13/64" and straight, not tapered. At the top, the hole is 1/8" and as you can see it goes all the way through. No idea what that's about.
Anyone know anything about these?

Or, they could have simply been hand made using some left over tubing as starter msterials. The 1/8" hole was there all along while the larger hole was bored to accommodate the arrow shaft.
A long shot, predecessors to a form of pin nocks? Maybe expermential?
Or....for Robin Hoods. Corral that point right down the middle
Don’t know anything about them, but I wouldn’t want those rough looking things riding on my bow string!!!!!
Bisch
Just throwing it out there.....perhaps nocks for Frank Eicholtz's first fiberglass shafts?
Look like they could be fitted with a post/plug and inserted into non wood shafts. Just a guess.