Found a list of post 1945 units but it doesn't really give any details about 323 company.
c1953 : 323 Company MSO : Germany : Latvian
Royal Army Service Corps» Companies 131 to 500
But emblems on badge are for :
Estonia - Blue/Black/White
Latvia - Carmine Red/White/Carmine Red
Lithuania - Yellow/Green/Red
One interseting point is that during Soviet occupation (from 1940 - 1990) the use of the Latvian national flag was suppressed.
" During the period of occupation by the Soviet Union (and briefly by Nazi Germany), the red-white-red Latvian flag was rendered useless from 1940-1941 and 1944-1991. Any production and public display of the nationalist Latvian flag was considered anti-state crime and punishable by law."