Anyone ever heard of one of these? I can't figure it out. It has three wings, so not M bayonet mount. Not sure what it is exactly. When you focus the entire front of the lens elements, as 12 blade aperature (4.5-22) seem to move all at once. It is old, black, brassing. It has a metal gray hood that says "lens made in france" but may not be original. Any ideas? It is rather small, I thought C-mount maybe. I don't have any pictures (yet).