Link for you. Collecting and Shooting the Mosin-Nagant 1891/30 - HISTORY
As far as who it was issued to- originally Private Ivan Ivanovich, assigned to the 7th Godless Horde. (OK, just kidding)
These rifles were made by the millions. The Soviets ran them back thru the arsenal after they had been replaced by the SKS and the AK, refurbished them, and put them in storage for the past 50 years. No way to tell who, or what unit had them. Somewhat ugly, fairly crude, good shooting rifles.
There are also carbine versions of this rifle (shorter barrels)