I believe it was used as a token for something, similar to the coal miners checking in and out at the mine. Just a guess.
I wish you did as well. Those numbers could mean so many things. Some counter stamps can be traced but others can not.
Aircraft SN. Martin B-26B-4 Marauder. Built 1941. Crashed 4 Jan. 1943. 18 miles N of Andalusia, AL. Crew bailed out. Crew survived. Plane scrapped. Crew names available. That is all I got...don't like, it, well, then it is National Archives SN Identifier for the 1945 List of woman prisoners of war. Germany Military District-Office Of The Signal Officer. US. Don't like that one either? Doityourself.com.