jml: The square with "X" inside is the mark of Arsenal #2, Kiev, Ukrainian Sovietrepublic, according to Alexander Yuschenkos recent book. This and other facilities repaired rifles during the war but large refurbishment programs occurred long post war. The same reference indicates your scope is manufactured by Factory #297, Yoshkar-Ola. The date is the first two digits in the serial- 1944. it was also refurbed. I would recommend this book if you plan to collect wartime 91/30's (title = M91/30 Rifles and M38/44 carbines in 1941-45). There may be some of them showing up in places like e-bay or alibris.
Ridolpho