Mention was made of the Redfield sight that goes on the right side above.  I think when Redfield made the transition to alloy, circa 1965, they dumped the whole no drill and tap idea, with its complex cuts and extra hardware and went with a couple models of alloy sights, one with coin slotted 1/4 minute knobs, "The Trophy" and another, "The Record" with set screws to lock the adjustment.  They went on the right, like a Lyman and required drilling and tapping.  They didn't last long after that switch to alloy, until 72.  There was a period, just before the change to alloy, that they made a steel model 102NK, that fit the Norwegian Krag on the right side.