During WW1 the realities of new modern warfare saw the return of metal armor on the battlefield. All countries of the war developed new metal helmets for their armies. The Russian Empire did not develop it’s own helmet but was supplied with French Adrian helmets which the Russians soon began to replicate their own designated M16 helmets. After the founding of the Soviet Union the new army continued to use the M16 with newly decorated communist badges. This helmet was used up until the mid 1930s when it was replaced the new SSh 36 helmet.
However just because something is “obsolete” doesn’t mean it disappears with a poof, as well as it takes time to reequip a whole army with the latest equipment. The Soviet Adrian continued to see use and some Soviet units still had the old helmet during the Battle of Khalkhin-Gol, Winter War, and it is entirely plausible that some helmets found their way into the early stages of WW2
Since this helmet was basically obsolete by the time of WW2 and rare I don’t think it should be a common basic cosmetic available for all soldiers. I mean do you really want to see every single Soviet in Berlin 1945 wearing these. However because of it’s unique appearance and history I think it would be perfect for a unique Premium/ event squad. I would recommend this squad to be a Riflemen squad
Since this squad is wearing a “foreign” based helmet I think it would be an interesting match to give them a similarly foreign weapon as well. This squad could have the Japanese Type 38 rifle. Russia has long acquired Japanese rifles and in particular the Russian Empire had purchased over 600,000 rifles. This is similar to the Premium Engineer squad armed with Type 38 carbines. The Soviets already have various foreign content mainly in the form of lend lease and since the Type 38 is already in game it should be so simple to implement