Your Mosin HAS been re-arsenaled at least twice in its history, if not three times.
The modifycatins and markings say so.
Built in 1893, if it were not updated, would look much different
As well, in 1893, it had a swivle for the sling on the front band and front of the magazine housing. They were relaced whith sling slots and estchons to proctect them were intalled and the rear sight base was the "flat' type.
First it went back to an arsenal to recive the 1908 updates, they removed the finger rest behind the trigger guard, and added the handguard, the sling slots and the hand guard retaining bands.
The recoil bolt being added to keep the stocks from cracking, and wood relived from behind the tang of the action, also to prvent wrist cracking.
The 1893's flat rear sight base replaced with the 1908 spitzer calibrated 'sawtooth' type. The old round nose bullets in the 7.62X54r changed to spired "spitzers" that had a different trajectory.
That was what the Imperial Russians did whilst in their service.
Then it saw alotta action and ended up in Finnland, with it being captured during a battle, captured at an old Imperial armory (Finnland emerged as a breakaway country when Imperial Russian dissolved) in the newly established Finnland, or bought in the 1920's from a Europen country that had fought Russian in WW1, and captured ,or so on, where it went to an arsenal and brought to Finnish spec, the chamber throat relived for the ever so slightly longer "D166 round" as noted by the 'D' struck to the barrel,(?is it?) the rear sight remarked, the arshin measures struck out, then inspected and the Bolt knob serialed to the rifle in the Finn manner, then test fired for accuracy and function, then issued for military service.
Then, possibly after the war , but before storage, or in the feild, (who knows) a Finnish army armorer went a swacked an "Box'd SA" as a Soumi Armee (Finnish army) property mark.
After the war , it was again inspected, parts replaced and repaired and able to shoot 5cm at 100 m, cosmo'd and stored ready to issue, no matter how ugly..... All the Finns cared about was bore condition and accuracy. Every Finn Mosin that was imported came here with a great bore, of the Finns would have recycled the parts. Most any Finn Mosin with a bad bore was ruined in this country.
Soviet refurbisments were much more, with stock replacemnets and reblueing, elctro penciling and black paint touch ups, shalacking the woods and crateing them up.
The soviets converted M-91's int 91/30's during the refurbishment programs, The Finns kept them "as is" unless it was drastic.
Great Rifle, and its history is excellent, much more than a rifle that was racked in a museum and never updated or used in combat.
The Finnish AWSOME square Buckled M28 sling and "dog collers" that attach it to the stock are worth up to 2X what you paid for the whole thing, You got a most excellent bargin AND a Finn M-91 to boot!!!!
GREAT SCORE!!!