Sling Swivel with loop buttstock Winchester 1866, 1873, 1876, 1892, 1894, 1895

This is the hard to find ORIGINAL sling swivel with the base and wire loop. It is placed on the buttstock of the Winchester 1866, 1876, 1873, 1892, 1894 and 1895.  Model  55 64 70 and others.  Some of the models came standard with this from the factory and some it was an upgrade option. It is held onto the buttstock with 2 screws, part number 626A.