The pictures of the Flaps etc. shows the dreaded Janitrol Cabin Heater it ran if my memory is correct ran on neat 100 octane fuel straight from the wing tank which was ignited by a spark/glow plug and ran like an over blown blow lamp which heated up a canister and cold air passed around it and was hopefully heated up and blown into the cabin, the exhaust went over the side at the external end of heater leaving an ugly sooty stain down the side of the a/c,{[where was health and safety then? they were lethal,unreliable at not very effective same for the loading steps at the nose. the last aircraft I worked on having a similar system was the Airspeed Ambassador but that was for the Anti Icing of the leading edges of the wings and tail plane only. The External supply socket was I think up in the starboard wheel well and you had to stand on top the wheel to connect and disconnect the heavy trollyac lead, just the job on a icy cold morning you tended to comedown faster than you went up.