Unknown Mexican Sterling Mark on Box

[treasureseeker24]

Looking for help on the maker mark on this box and if anyone may know what this box was used for. I was told this box was given to a bride and groom when married and it would have a gold coin inserted. This was said to be good luck. The box is about 1 3/16" x 7/8". The mark is sterling mexico with a crown above. Any help would be appreciated.