psteinmayer:  You may be able to salvage the original sight holes on your Krag barrel.  Normaly these were simply filled with sight screws that were cut off and the shanks filed to the barrel contour.  I have removed these from four or five Krag barrels by locating the shank, center-punching it, drilling a smaller diameter hole deep into the shank, and tapping a small screwdriver blade into the shank and turning out the screw-shank.  Heat and penetrating oil helps the process.  If you can salvage the holes and threads, you can mount an original sight or long eye-relief scope mount.  As Dick Hosmer reported, the Krag receiver scope mounts have to be off-set.  This limits you to old Weaver and William's mounts.  In my opinion, they are clumsy and ugly.