Just arrived, got this High Voltage Regulator from a well known aviation historian and author of books about the same.
Used in the passenger compartment of Mosquito Mk6, G-AGGF used by BOAC on the "Bearing Run" to Sweden during WW2, carried a single passenger in the converted bomb bay, and from what I'm told, used to change from Light, to Oxygen to Heat by the passenger in the tiny space.......
Unfortunately this aircraft crashed on 17th August 1943 after getting lost over Glen Esk in Scotland. Killing both crew...Captain Wilkins and RO Beaumont...
Lots of info on the web about it...
https://aviation-safety.net/wikibase/18796
The photo of the aircraft getting ready to take off, is supposed to be the night of the terrible crash....their is obvious fire damage to the regulator...:(