Difficult plot ) If the goal is to make a campaign in this specific era and somehow connected to real historical events, it's not a problem. But if you want to write something really close to real culture and people in USSR - it's impossible. All the mentioned scenarios, with all respect, are "cranberry". I can try to explain what does this means (cranberry). If you look at Bollywood movies and think that life in India looks like it for real, well, it's "cranberry". Vodka, balalaika, bears in the street, matryoshka, nuclear reactors in each household - cranberry. Any native speaker, when he reads any of the mentioned campaigns will notice "cranberry" because of the names of main characters (not all, but most of them). Of course, I'm not talking about more detailed work with cultural aspects of everyday life.
But my advice will be really bad without any positive feedback ) What can be really interesting and could work well - US and UK intervention to the Soviet North in 1918.
https://en.wikipedia.org/wiki/Allied_intervention_in_the_Russian_Civil_War
Long story short:
End of the Great War.
The civil war in USSR. Two main forces - the White army and the Red army. More easily - ex-Imperial forces, protecting the old system and communists on the other side.
Allied armies invasion to Murmansk and Arkhangelsk (in English it means Archangel) to support the White army.
In this case, you will have a lot of common and well-known culture in your campaign from one side (the US and England troops + Canadians, Australians + some french colonists + a lot more other small ethnic groups) and USSR setting on the other side. From March 1918 till November 1919 at minimum, your players will be able to visit a lot of northern Russian cities and make some mythos related story out of it. Your players can be any nationality, you will have danger all around and some isles of peace in big cities captured by Allied forces.
Just, for example, "Frankenstein: or, The Modern Prometheus" begins in Arkhangelsk (original book). Also, you may find inspiration in the last episode of "Love, Death & Robots" - «Secret War». It's pretty close to not a "cranberry". Please, welcome, if you have any questions.