I've sent an e-mail to the Parham Airfield Museum (Framlingham) in Norfolk, asking if they can kindly provide approximate measurements of the S-1 bombsight they have on display there. Hopefully I'll get a reply if or when one of the volunteer staff has a chance to measure this bulky item.
And back to the build, with some initial work done on the fuselage.
The applique armour on the exterior cockpit sides has been replicated, with 10 thou (0.254mm) plastic card being cut to shape and attached using Tamiya extra thin liquid cement. The attachment brackets along the top edge of each panel have yet to made and fitted, and some clean-up of some of the engraved panel lines also needs to be done.
Next step involved planning and measuring for modifications to the waist gun area.
The kit-supplied "tub" is reasonable, but the sidewalls extend too far aft, and the floor includes two, open, ammo boxes on each side, and a chest-pack parachute on the floor (a 'chute would never be left in an aircraft).
The (plywood-covered) side frames should end just aft of the rear edge of the waist windows, and there were two, vertically stacked ammo boxes on the starboard side
only, immediately aft of the window, each with a stainless steel, tubular-framed ammo chute leading to the rear turret feeds.
Consequently, part of the wall on each side needs to be removed, along with the moulded-in ammo boxes (and the parachute), the aft end of each wall needs framework added, and the resulting "missing" floor section will need to be rebuilt.
Once that's done, extra fuselage frames and stringers will be added to each side, and then the vertical ammo boxes and feed chutes will be fabricated and fitted.
The pics below give an idea of what's required, and where, and I hope to start work on this tomorrow (Sunday).
I need to provide Bill with some scale info and photos, as he's kindly preparing the artwork for the nose art and code letter decals, which he'll have printed for me, so I may not get much actual modelling done, but we'll see.