Howdy,
I have a question that is not about woodworking, but many of you are tool folks, and so, I thought to give it a try...
A traditional cobbler's hammer (often called a Crispin pattern hammer) has a round face (for striking) and on the opposite side of the head a flat curved part that is of tapering rectangular cross section.
(That part is rather like the claw of a framer's hammer, but with what would be the two legs of the claw together as one piece.)
On some of these, that curved section does not drop very far at all and so its narrow end could be used for striking.
But, on some of these hammers, that curved section droops down so far that it is parallel to the handle.
In that form of the design, it cannot be used to strike anything.
What then is its purpose?
You can see the shape I am describing on the left here: