Looking at the abysmal sanding of the butt as typified at the heel of photo 9, probably done by a butcher on a a sanding belt, I'd bet that it was done at some factory in Asia - probably Pakistan! Then hurriedly coated with the usual coats of cover-all varnish. Yep, that says the Indian sub continent somewhere to me!
So far as the charger bridges go, we used to lever the bridge with a bar of steel (usually the stockbolt screwdriver if I remember correctly.........) and the faintest oil squeeze around the edge would consign the rifle to one side where a small hole would be drilled into each side, between the body and the 'loose' bridge. EXACTLY as shown in JM's photo. It'd be countersunk and then arc welded across. Lightly made off with the linishing wheel, it'd continue on its path through the workshop process. This process always showed through the phosphate process but would be covered by the paint. Done zillions of them!