"Exile stamps" issued by General Goppers Foundation.
"General Karlis Goppers (1876-1941) was a Latvian military officer . He was the commander of the 7th Bauska riflemen regiment during World War I and commander of the Vidzeme division of the Latvian army, from 1924 to April 1934, when he retired.
In 1940, after the Soviet occupation of Latvia, a special officer was appointed by the communists to abolish Scouting. Scouting continued unofficially and underground, operating without uniforms and in the forests to avoid detection. On 30 September 1940, the NKVD arrested General Goppers. He was sentenced to death and on 25 March 1941, he was shot in Ulbroka forest"
Some info here :https://sossi.org/exile/latvia.htm