Hi i hope this is the right spot for this question. I just bought a Clausing 5914 that came with a 6 inch (might be 6 1/4. forgot to measure it) in3 jaw and an 8" 4 jaw. Both are L-00 mount. The 8 is Poland so I know that's a older Bison. The 3 jaw has no markings on the chuck face or body. There is a recessed circle on the face where there was probably once a label and in that recess is stamped numbers (s/n I presume) and Made In Eng. See pics.