Thanks for the comments, Gents . . .
@Frank; I wouldn't know if it was itallan or not, but I did make a thorough study of both of the books about Supermarine projects and prototypes written by Ralph Pegram . . . and yes, the rear prop is backwards, I just used the props that came with engines, and hoped that no one would notice . . .
@apophenia; that was one of the 'few, minor niggles'. As well as being cold and draughty, the strong slipstream interfered with gun aiming from the dorsal position, so much so, that the position was not manned unless absolutely essential, which in peacetime, meant never . . . the tail position was not as badly affected, however, so was occupied when necessary.
cheers,
Robin.