It reminds me of some old roofing hammers I have seen.

Yep, its a shingle hammer/hatchet.  They used them when a lot of roofs were cedar shingles.  The cost of cedar vs. asphalt has largely rendered them obsolete.  I actually take the time to cut my shakes (cedar shingles have become rare as well, now most cedar roofs use taper sawn shakes that are twice as thick as s shingle at the butt end) down on a table saw now in the rare occasion I do cedar roofing.  Of course we no longer bang nails in by hand either.