As we seem to be in an inflight-catering mode, perhaps I can mention the Type 52 Resistance unit as used in old flying machines which used the Receiver R1155. This unit dropped the aircraft 24v down to 18v for said receiver, while the T1154 used the full 24v whack. It was a circular unit, open at the top with a wire mesh. In the UK it was very handy for warming things like pork pies, but not so much use in the Middle East. We - dare I say it? - ate them with our bare hands, although the commissioned crew members may have had a china plate, knife and fork and pristine linen serviette. In the ME we had the ubiquitous white box with, probably, 2 buttered bread rolls, a piece of fruit perhaps and always a hard-boiled egg. How I loved those eggs; look to the rear out of the astrodome, remove Verey pistol and release the egg through the hole. It flew under the tailplane IIRC and landed somewhere in the sand below. It is rumoured that one of our navs, a reconstituted WW2 veteran with an 'O' brevet, could follow the trails along our routes.