looks like the Fisher body logo, but not quite.

any ideas?

jul232 by Skip Albright, on Flickr

Since GM  and Fisher bodies used wood framing clear into late 1930s, the upholstery guys would have used tacks until then.  I would bet every Fisher body plant had dozens of such hammers. 

Yes that is in fact a General Motors Fisher Body Division tack hammer. I have one like it, They show up at garage sales occasionally around these parts ... Detroit Michigan

Joe B

Man i`d love one of those...nice find.