Sad to say progress has been zero for some time now.
I rather foolishly decided to re-build the model room to make more space for my 5' long 1/144 Atlantic Conveyor and as a result ended up with less room to do anything else! Even worse, in the re-build I managed to LOSE the 'Whaleback' and the only part of the kit I can find is the Oerlikon, which surfaced in the Airfix Whaleback box of all places.
The search still continues, when I'm not building something else, so hopefully there will be other reports before too long.