John,
It's nice to see the Ketland lock with its original chisel-cut "V" slots in the cock screw and top jaw screw, along with the expected tapered end on the top jaw screw. Just in case you weren't aware, most early Bluegrass guns from central Kentucky... where I collect from... used small "T. Ketland" locks just like this one, usually about 4-1/4" long. So John, why don't you measure the length of this neat little lock and post it, and when you get tired of not finding a gun to put it on [probably since most that would use it are in my gun safe], why don't you pass it along to me? Just a thought.
Shelby Gallien