I don,t believe that they are factory mounts but rather a copy of factory mounts as the pivot pin is in the center of the mount rather than offset to the left side like the factory mounts. I have several sets of mounts as well as having seen many others and many original catalog pictures and they all have the offset pin. Making rings and bases for the offset pin requires very precise machining whereas the center pin would be easier to manufacture.

Not trying to hang shit on your rings, I just don't believe that they are factory.

Kuduae might be able to add to this.

Matt.