Nearly bid on those myself. I have a spare bunch but am 5 nuts short. (no jokes please):D:D

I have bought a few of these HZ GTS nuts and there are no part numbers at all on them. I have got a couple of different types as well, both I believe are original.

How to tell. Mmmm, I think the repo ones have a different groove cut into them. It seems to be a squarer cut.