FWIW: During WW-1, Krag rifles were widely used as training rifles. Some Krags were 'called back' from settings, like military schools.

Some of these rifles had broken or damaged parts. Rear-sights and sight-knobs were especially vulnerable.

IMHO - To make these rifles, (and Krags that were stored in reserve), useful, they were probably inspected and repaired By Someone - Somewhere.

I am not aware of anyone or of a reference that totally addresses this subject.

I am not talking, strictly, about the well structured and organized process of 'refurbishing' (IRAN - inspect and repair as needed), that was done at Springfield Armory, arsenals, and depots, pre-1914.

It is my suspicion that during WW-1 some expedient repairs may have been done at training camps using even obsolete parts.

.... and I could be totally wrong.

(Seemingly - The model 1898 rifle and carbine sights and the model 1898 sight-bases should have been totally obsolete. The 'ramp-curvature' of these bases was wrong for the trajectory of issue ammo.

On the other hand - When Krag ammo started being available as "Palma Match Ammo" and with 180 grain Spitzer bullets, all sight models were probably obsolete in their calibrations).