Old unusual Darbys

Here's a pair of old Darbys that I've never seen. The key is marked "No. 27" in the old style (circa 1820) No maker's marks, but on one cuff near the hinge "wrought", on same cuff near link "warranted" On both cuffs, at a slanted angle near end caps "Hard". The center link is hammered. I got these at a gun show, and the lady was selling her late husband's guns, Indian artifacts, and, according to the other dealers who knew her, everything was absolutely authentic. The bad news was that she said she had sold the matching leg irons a year before! I paid $150 for the cuffs, she said the leg irons went for 300.