I did find one other example of this mark, but it was also a mystery. I also found an electric company who made tools, non sparking hammers etc and their symbol is an M in hex with an arrow.
I found the logo. Its 1920s to 1940s. The logo is the weatherhead company logo from Cleveland ohio.
The hammer appears constructed professionally, so either weatherhead made, or a machinist made it using weatherhead stock part from a tubing tool of some sorts. This hammer did come out of the 1940s snap on machinist tool chest.