Dave,
It is curious, but very stout.
The answer comes in two parts:
The part clamped on the scope is for a revolver.
The part mated to the rib is custom and secured with three screws.
It is not a quick detach mount. This suited the first owner who shot deer (sighting with the scope for the right barrel only with 300 grain Remington bullets) with this rifle for 10 years.. His widow told me his blind was in the middle of their property and he always brought home the venison. In fact, he was dragging out a big buck when he had a heart attack and died in the field with his deer and rifle. Sad, but he went doing something he loved.
Otherwise, I would never been offered this like-new rifle. 10 years and only one tiny mark on the butt stock!
Anyhow, my son and I are trying a few different loads to see which works best for us.
