Acquired a copper version of 2M-306. I’m not sure why M&R lists two medals (silver and copper) with the same identifier. A set will most likely be broken. I believe the silver mate to this copper medal was melted for its silver content. Once again, this visual example will help you correctly identify 2M-306. Also, if you compare the description of 2M-306 (page 120 of M&R) you will see the discrepancy in missing information.  Enjoy!