Geriaviator,
Lovely pic of a sturdy old aircraft ! Two items puzzle me: what is the thing on the wingtip aft of the nav light ? And it looks as if the exhaust stub has a shroud round it (obviously a heater of some sort), but the outlet looks as if it is going into the wing root - presumably ducted from there into the cabin ?
As for the Wellington - Oxford transition, we said the same for the Spitfire > Harvard !. I am not sold on the dummy control idea (I never met it).
Sufficient to the day is the evil thereof ! 
Danny.