Since Brno (know as it's german name of BrĂĽnn) was still in the German empire, the early (pre-WWII) Brno 21/22 have Waffenwerke BrĂĽnn Aktiengesellschaft marked on the left receiver upper wall. This one was made in 1942, in a time where sporting rifles were made in very small numbers. Sad it's so much pitted, though, as it removes a big whole part of it's value.
The 21/22 were made from about 1937 to 1940, then in small number until the production resumed in 1946 'til it was discontinued in 1950. About 1948-9 the production was from shelved receivers as the ZG47 started being produced.