Want to know how internally corrupt was Soviet system? Watch Soviet Jeans! Though set of events may seem exaggeratedly concentrated, actually its based on true stories. Even more - one of the actors himself spent time in Soviet mental institution when young.
Also look for memorabilia, premises, decorations, use of landline phones. You get the feeling of being in 1979.
And , frankly, the series is not in Latvian. I've never felt so natural mix of three languages seamlesly used in one film. Latvian, Russian and English follow each other than o e stops noticing it. Just needs to read subtitle when unknown tongue sqeezes in.