So that mean the mosins used in the war that were converted to this design were modified from a standard point, and does that mean the mosins of that design are less historic, than the standard counterpart? i dont think so, because i know for a fact that they would test a group of mosins and the accurate ones were taken to be modified to the sniper version. this process was done in our own military as well, to convert rifles without a scope to a scoped rifle, maybe not the bolt bending. but it still seems that if a military can do it, and that rifle is accepted it should be ok if i do it on my mosin.
ok first of all, the modifications that you list on the mosin nagant for sniper was done by the russian government and it was done before the rifles ever entered the hands of soldiers. and they served their roles in wartime. as such they still hold historical value in that condition and in most cases are even more highly sought after because of the relatively low numbers that they were done in compared to their general issue counterparts. none of those rifles were converted to snipers by the joe schmoes weilding them and none of those soldiers chopped down the stocks, added thumbholes or took them to a local gunsmith to be drilled and tapped. the use of these rifles in wartime is what gives them that C&R value in the first place.
secondly, that was not the process used in american sniper rifles. the remington 1903A4 was designed from the ground up as a sniper rifle. they got random barrels, they were all drilled and tapped and they all had different bent bolts from the standard 1903A3 to allow for scope clearance. they were not built as a 1903A3 and then tested for accuracy. the same goes for the winchester model 70s that were used as snipers by the marine corps. they were built from the ground up for the task of being a sniper rifle, not front line battle rifles.
taking a can of spray paint and a hack saw to one of these guns in your garage and then taking it out to kill prairie dogs is not the same as setting up as a sniper in a factory and taken out to kill Nazis.