Soviet Souvenir, 1939
This Bakelite box is a souvenir from the 1939 Всесоюзная Cельско- Xозяйственная Bыставка (BCXB), the "All Soviet Union Agricultural Exhibition", held from 1939 as a permanent exhibition of economic achievements. The building we see in the commemorative stamp in the background was built in Moscow for this fair.
This beauty was made in the "plastics factory number 5", as marked on the underside. I wonder how this item traveled so far in space and time in mint condition, to be found in a Brazilian thrifts fair for less than US$2. Too bad, no sickle and hammer on this.
It measures 10 cm in diameter.
If your Russian is up-to-date, please check the site of Ivan Kokonov, a researcher on BCXB who kindly gave me the explanations to all this: