Anyone ever seen floor tom leg mounts like this? They seem to work but have never seen these with the vertical split down the side and the entire lug squeezes shut when turning the drum key. I`ve owned a few Fibes kits from the 70`s as well as Darwins/Corders and never ran across these.

Are they just a 'one off' or rare production? My guess is a talented machinist took matters into his/her hands but no chrome seems to be missing or flaking off.

Any help is greatly appreciated.