[Update]
Got the rifle in just yesterday and boy golly, was it a piece of work. Literally all exposed metal was rusted and all screws/ wood contacting surfaces were rusted to all get out. Unfortunately, this meant almost total destruction of the stock to remove the barrel and receiver for cleaning and proper maintenance. The rifle body itself (stock removed) is severely rusted and for all practical purposes, unshootable in its current state. Major work and replacement of parts will need to be done to return it to a usable state.
Initial observation of the stock revealed several splits near the rear of the receiver and rotting of the wood around metal bits. Screws were rusted badly and have yet to be completely removed for fear of snapping them in their threads (already managed to do this with a capture screw
). After removing the stock, I found severe rusting and pitting on all areas of the rifle body. I honestly doubt it can be disassembled without breaking but I guess we will see tomorrow. The barrel was effectively a smooth-bore but rust free, at least on the internals. The receiver appears to to have no rusting on the internals. Bolt has a broken safety lever as well as a very mild amount of rusting. The rear sight is completely trashed, but I was able to remove it. Front sight is missing its' protective hood, but otherwise appears serviceable.
It is a shame that this rifle was left in such disrepair. It appears to have been dropped in a tank of brine or the ocean and set in some storage room for years, without ever being disassembled or cleaned. I would honestly much rather be cleaning out cosmoline than dealing with the rust pile, but such is buying milsurp.
Additionally, I thank everyone who took the time to assist me in deciphering those markings. I've learned a lot and am grateful for your input!