I think Maddog is on the right track, It could have been for a sight intended for something else, a sight would not require holes in the barrel. It also could be for a Stith mount, they made one for Winchester lever rifles that used narrow hole spacing, but the ones I could find use three holes, but that doesn't mean you have to use all three, again no holes would be need in the barrel. The Malcolm scopes used just one hole that is larger than those.

Here's one for Winchester 94, it's offset to the left though - /itm/Stith-Scope-mount-

Here's another similar - gunauction.com/buy/9862948

Both of these appear to need holes in the barrel, but I think a dovetail mount would work as well.

Last edited by GeneB; 01/22/20.
Gene