Yep, I should have clarified - the RAFM example is a T.10 navigation / radio trainer, which originally had a 'solid' nose, the front turret being a later addition from the first restoration for display, to represent a 'typical' bomber configuration.
As mentioned, from those WW2 photos I've seen, and wartime footage, there was a 'solid' bulkhead over the insulation, directly behind the pilot's seat, as provided in the kit parts.
Incidentally, the RAFM Wellington was the actual aircraft used in the movie 'The Dam Busters' (still in overall 'silver' with yellow 'trainer' bands) for the scenes depicting Barnes Wallis and 'Mutt' Summers testing the first bombs.
Note that the Brooklands Museum web-site had a 'virtual tour' of the 'Loch Ness' Wellington, but I couldn't find it the last time I looked.