I've just been reading A Pictorial History of Pan American World Airways by P. St John Tuner. At the end of Chapter 6 (Clippers to Europe) he says that B-314 seaplane had a flight deck the size of the DC3s passenger cabin, 21ft 4in long 9ft 6in wide with seven work stations. The crew consisted of Captain, First Officer, Second Officer. Navigator, Engineer, Radio Officer & Junior Flight Officer. I don't know how often supplementary crew would have been carried. The typical passenger load was 35 so that's five passengers per flight crew member. Things gave changed a bit since then!