Upvote:1
As so often, the answer depends on the specifics. You ask about pre-WWII, yet you mention the GULAG Archipelago published in 1973, long after WWII.
On the other hand, quite a lot of people were all to aware of the shortcomings of capitalism, from the Great Depression to capitalist sponsors of the Nazis. Quite a lot of whataboutism going on.
Upvote:2
It is not clear what exactly you are asking. One thing is the knowledge AVAILABLE, I mean available in principle, to any Westerner who takes an effort to search it. Another thing is how much a random person in the street, who reads major newspapers knows. I do not think Orwell had special access to any information that was not available to other writers on Soviet Union. The problem is with what they wanted to know and see. In all periods of existence of Soviet Union, there were people who escaped from it and published books in the West. But "general public" either did not believe them or did not care.
The fact is that "public opinion" was deceived by Soviet propaganda, very much helped by the propaganda of many left-wing Western writers of high standing. Most people in the West do not realize that Soviet Union (and Modern Russia) has an enormous State-sponsored and highly effective propaganda machine on the scale unimaginable in the West.
To put is short: adequate reports of what is happening in Soviet Union were always available in the West, since the very beginning of Soviet Union. But they did not receive wide attention, for several reasons which I outlined above. And were unknown to the "broad public".
Upvote:2
Politically oriented proletarians in Western Europe were well aware of the nature of the Soviet Union and chose to support or oppose it based on their organised theories of revolution. For example, working class communists in Australia often supported the Soviet Union on the basis of preserving a revolutionary nucleus, rather than on the liberal appeals to intelligentsia that the Soviet Union was a wonderland.(Brecht 1930 The Measures Taken exemplifies this knowing revolutionary defensist position) This can be evidenced by the rapid decline in support for the Soviet Union due to the Molotov-Ribbentrop pact, rather than due to purges or famines. Right wing social democrats and labourites opposed the Soviet Union based on the large and available non-Bolshevik left emigre literature.
The material was available, cf Strauss /Soviet Russia: Anatomy of a Social History/; Koestler Darkness at Noon; Koestler The Gladiators; the betrayal of the POUM and then CNT-FAI. Let those who had ears, hear.