You may be right though interior photos of British aircraft are not that common so I would not rule out an aircraft fitment. I suppose there is a list out there somewhere of which aircraft carried both Gee and Rebecca which would narrow the search massively but ballast (avionics, also known as boat anchors) was never of great interest for me.
Having the power supply for both units on a separate panel suggests a late model version of a type where they were a retrofit rather than an item that was in the original design.
What part of the world was if found? Newark UK or Newark USA? And if USA which of the many states with a city of that name.
If North America then it would suggest Canadian and they produced many submodels of the Lanc in very small numbers - from memory there were only two Mk 10AR aircraft for example (KB976 and ???) but it is unlikely to be from one of those as they were Arctic Research and definitely had no Gee, and probably no Rebecca.
That tag to the right of the fuse box appears to be Rotary Converter so is not much help (tho again Brit terminology as the Yanks would label it Inverter). A photo showing the 35 amp CB on the right and photos of the back may help also. Some manufacturers have little quirks that make it easy to say that is a xxx part. My substantial Brit experience is unfortunately limited to Anson, Beaufort, Beaufighter, Bolingbroke (Blenheim), Dove, Heron, Hurricane, Lancaster, Lysander and Spitfire and some minor, mainly wooden, types.