Orwell's job during WWII was to translate news broadcasts into Basic English, with a 1000 word vocabulary, for broadcast to the colonies, including India. The British had a scheme at the time to get everyone in the colonies to speak at least Basic English, and this was part of it.
Orwell observed that translation into Basic English is a political act. Some concepts are very difficult to express in Basic English. Political ambiguity does not translate at all.
As for "part of the horror of his picture of 1984 is his eloquent description of the low quality of the gin and tobacco," that comes from the Ministry of Information's canteen, described by other ex-employees as "dismal".
"Big Brother" seems to have been a senior staffer at the Ministry of Information, who was actually called that (not to his face) by staff.
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