Rear sight shaving tool

I dont know how many here have seen one of these but I used it recently to fix up a fairly brutalised 1903 rear sight. It fits into where the rest sight base and with two sets of adjustable teeth skims a little off both faces of the lip of the collar where the windage graduations are. I suppose they would have been used if the collar lip got damaged or perhaps all new sight collars needed to be precisely skimmed before installation of the rear right.
It is marked, Rear Sight Shaving Tool US Rifle 1903 A1 1944. and came from a gunsmith in New Zealand who received a stack of the NZ armies 1903 spares when their 1903 were disposed of. It shows the NZ forces were still receiving 1903's or at least spares in '44.

Happy New Year everyone