I've had the pleasure of flying in a de Havilland Dragon Rapide a couple of times. It was lovely, and I can well imagine hopping around Europe in it. It really doesn't take more than a handful of minutes for the last set of travellers to leave, and the new set to board, even if it is a surprisingly uphill walk! And, in this case, no First Officer. Just Biggles up in the single pilot's seat.

Incidentally, London-Amsterdam-Hanover-Berlin would have had the Rapide running on fumes, so it would have had to have been refuelled at some point. I'm not sure whether this would have been done from a mobile bowser or at a gas pump. (I've fuelled planes from a gas pump before now, but only light aircraft.)