Ralph Pegram’s ‘Beyond the Spitfire; The Unseen Designs of R.J.Mitchell’ describes Mitchell’s design for B.1/35.
It had a narrow fuselage less than 6ft at its widest point and carried its entire bombload within the wing to the rear of the spar.
It had three gun positions, nose, tail and dorsal.
The nose gun was such that the operator would have to lie prone to operate it due to the narrowness of the nose. With the tail position, although the operator was in a compartment in the base of the tail, the guns were operated remotely. There was also a third position in the roof that is thought would be a retractable mounting.
Power would be from two Twin-Aquila sleeve valve engines.
It would need different engines but is there any potential for the design to actually be an unarmed speed bomber?