Carl, The reason everyone, including me, is interested is that the only known 4 in. wood handled monkey wrenches are the so called "baby coes" wrenches and these are right at 4 5/8 in. long, not 4 in. The one you pictured looks a little out of proportion. i.e. the handle looks a little short compared to the body.
A couple questions, how far do the jaws open; how long are the jaws; and what is the length from the top of the fixed jaw down to the bottom of the adjusting nut? Also how wide and how thick is the bar? I can check these dimensions against a baby coes and see how they compare. You never know when an unknown wrench will surface. Maybe this is it.
Mike