I have come across these dies, or at least I am pretty sure that's what they are. They are smaller in diameter than standard dies, as far as my knowledge is aware anyway. If I am not making any sense then I can measure them and post that if need be but they are too small for standard die lock rings, and the threads are different. I have no idea what they are or what they are worth and hope someone here can help me. I may be selling them later as well. The only marking I can find on these are shown in the pics. Any help will be appreciated.
Thanks
Robert