Can you give us some closeup shots of the peep sight and tell us whether the screw holes will line up for the 48K. My lovely little Krag sporter has a Redfield peep which is very nice, but I would replace it with a 48K if the holes were identical. I have always thought that my Krag was a Stoeger conversion, but I have never taken it apart to look for clues.
There are no mounting screw holes for the Redfield sight. It is their old "No-Drill" sight that employs the side plate screw hole and a clamp into the vacated magazine cutoff spindle hole. The Lyman 48 will require two d/t'ed screw holes, and I'm waiting on the mailman to deliver the carbide drill bit needed to pierce the notoriously tough hide of the Krag receiver (hedging my bets a bit by carefully spotting the hole locations with the point of a Dremel grinder, quite possibly the only sane application of a Dremel in gun work, haha). The side plate will interfere a bit with the Lyman sight base and will require some re-profiling which is a normal protocol as far as I know.
The Redfield is a darn good sight, once zeroing has been achieved because adjustment is crudely effected. The Lyman 48 is leagues ahead in that regard, my only wish being that they had made it a "No-Drill" design for the Krag.