FWIW - My take on this overly complex sight-arrangement. (Sights fascinate me).

Picture #1:  A 'modernized' early bolt collar, that Springfield updated to take the later type of safety-lever was used.
However, our "Tinker-Gunsmith" reopened the 'filled' cross-pin hole. He used an early 'pinned' Safety-Lever.
The Safety-Lever and rear of the 'Peep'-Sight are retained by a cross-screw.

Picture #2:  The 'Peep' is a hole through the short leg of an "L" shaped spring. The spring is retained at the front by a large headed screw, which also allows it to pivot, sideways.
Windage is adjusted and locked by two opposing machine screws (red arrows).
Elevation is controlled by a numbered Knob. The shank of the knob may have four flats of varying heights (green arrows). The shank is retained on the right side of the sight by a 'slotted-washer/nut' and maybe a hidden pin.

Picture #3: The sight is held in place on the bolt by a cross-screw through the Bolt-Sleeve and by two side-plates that clamp the Krag Extractor. (Anchor-Screws marked with purple arrows).

BTW - This begs the question ... did this Sight require partial disassembly in order to remove the Krag's Bolt?

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