This pattern was a short lived WWII-era camouflage issued to some Soviet forces beginning in 1944. This particular suit is dated to 1954. This uniform was most often issued to special units such as reconnaissance, sniper or border guard formations.
While it didn't last too long in "official" service, this suit has been seen in use with Soviet troops as late as the Soviet-Afghan War.
All of these suits will have replacement buttons, rusty buttons or faded camouflage. This is due to long-term storage, their age and heavy use throughout the 20th century.