No expert, but I don't think the factory drilled them for receiver sights, just tang sights. I suspect someone had it drilled for a sight they had on hand. The .41 spacing is narrow, it was used on Marlin and Winchester lever guns, I believe post-war Remington pumps and autos used a wider spacing. In any case, you need the levergun sight, the cheapest route is a Williams, if it's sold for a Marlin 336 or Winchester 94, you should be good. I just returned a really nice Redfield 70 advertised for a Winchester 94 because the spacing was wrong. A 1966 Redfield brochure doesn't show any receiver sights for you rifle. Mine has the Marbles tang sight.
