...as it IS a kind of bombsight, why not set things up so that if the pilot selects crew position 2 they are given a view that looks like a bombsight but that points directly backwards from the top of the periscope head. Same ability to bank and turn from that viepoint as a normal gunner position, but the guns, obviously, are fixed. Of course, this shouldnt allow the plane to be treated as a multi-crewed plane.
Esme