Rote 8.
Sorry to muddy the waters further for you but I think the Station ORB is going to be essential reading for you. Bobbington, (Halfpenny Green), was, as you probably know, the home of 3 Air Observers school. This later was renamed 3 (O) AFU. During it's existence the unit operated Ansons,Oxfords, and possibly more importantly, the Blackburn Botha and Vickers Wellington. From late 1941 the unit increasingly received numbers of Australians, New Zealanders, Free French and, here it comes, Canadians. I'm just wondering here. To the civilian population of the time, both the Wellington and the Botha would have appeared to be large aircraft. Particularly compared to the Anson which must have been a common sight in the local skies. The Wellingtons issued to this unit would have been pretty war weary by the time they arrived and probably had a poor serviceability record. The Botha was seriously disliked by crews as seriously underpowered and renowned for engine failures which often resulted in fatalities. Now you might wonder were I'm going with all this? (I often do myself)! But there are lots of other possibilities that could cloud the local memory over that length of time and I think the official unit/station documents are really the only way to go to get to the bottom of this one.
Spiney
P.S. You'll really get a kick out of the research anyway.