I talked to an antique tool collector yesterday, and when the subject of blacksmiths vises came up, I remembered this subject on the forum. I asked him about the little clamp on vises like this one. He said some were military, often used by armors, and gunsmiths, and could date back to the Revolutionary War. And, others were used by traveling tinkers, and were often clamped on the bed of a wagon or cart. He also said there were mentions made of them being used on the trail west, to repair wagon parts, guns, and what ever else needed repair. Once again I suspect they were clamped on the floor boards of a wagon.
Hungry Horse