I flew quite a few times in the 104 when it did the LHR-SVO flights of old, and a few times within the Soviet Union. Yes, they were noisy, and there was always that strange smell on board. Many said it was boiled cabbage, but it didn't smell like any cabbage I'd ever come into contact with. Even in those days, they served chicken, with copious quantities of vodka, which helped to deaden the sound. Of course, there was always the additonal crew member - to keep his eye on the others...Although I've been told since that the radio operator was how can I put it - superfluous? That would explain your five crew Opssys - perfect description of the interior by the way - brought back a few memories!
The Comet was fairly quiet, quieter than the 104, which from memory (slightly clouded by all that vodka), had a high-pitched tone to it which was not present in the Comet.