Weston:  It appears a workable screw could be made for the Redfield #102 Krag "no-drill" peep sight by utilizing (sacrificing) a Krag or 1903 Springfield rear barrel-band/sling swivel screw.  Although as issued these screws are too long, they have the same shank diameter and 26 threads per inch as the Krag sideplate screw.  Overall length would have to be shortened to approximately 9/16" to replicate the Redfield screw.  There should be an adequate amount of thread left on the swivel screw you are shortening to engage the threads of the receiver.  It might be necessary to slightly reduce the diameter of the barrel-band screw head to properly seat in the Redfield base.  It may also be necessary to taper the tip of the altered screw since they were peened into place sometimes in their role as swivel screws.  Preferably use a 'buggered-up' screw to adapt as a replacement (you can dress-up the damage in the process of altering it).