I have a shooter-grade 23B in 25-20 that has holes in the left side that was apparently used for a side mount scope of some sort. The two holes are tapped 10-32, spaced 2.37" apart, and located at about the 10:30 position.

I'm wanting to find a mount that will fit and accept a 1" scope.

I tried to find info on fitment for the old T/N/U/etc letter-series Weaver mounts, as I'd prefer to have a one-piece, rather than the bulkier but still manufactured #2. The only thing I've determined is that the U are 1-inch, but I don't know if any will work with the 23B.

Does anyone know what side mount would likely fit without drilling more holes? Weaver #2 side mount base? Older Weaver U2?

Does anyone have recommendations for a resource on the older Weaver mounts?