Branson,
Looking at that drawing, I can see reference measurements on the little vise, although I cannot read them.
I can't quite make out the base, though. I'm running the steps through my head on what would be needed to forge one, but I think that base would be the obvious hardest part. To forge out the shank, and keep enough on there to forge out to make the pivot point for the other jaw, that would be the hardest, I think.
The rest of it, would seem to be a process of punching a square hole for the screw (I'm thinking use a carriage bolt in a square punched hole), round punched hole for the opposing side, and a hand forged wing-nut to tighten it.
The jaws would be a matter of upsetting and then splitting the parent stock, turning them out, and rolling them inward to form the wide jaws. Rivet the moving side into the base. Make a spring the same as a regular post vise, but on a much smaller scale...lol.
But that base has me stumped. It also looks to have a lip to hang slightly over each side of the anvil.
Of course, it would be tedious, to stay within the measurements, but could be done nonetheless.
I find the forging of tools like this fascinating. That's what got me started in blacksmithing....I wanted to learn about the process of forging tools by hand.
I can't wait to show a copy of this plan to some of the guys at the next conference. I know a few of them would really enjoy trying to make one of these vises. I'm considering making one to fit the hardy of my travel anvil, or a variation of it, to take to demonstrations.
Good stuff. Thank you for sharing it.