Nice one mate, it's the dog's! Sorry, I forgot to post those pics for you. The guns were mounted in blast tubes that were shiny stainless steel. You could paint the flat part of the muzzles red, as they had dust caps added to stop crud or ice forming in the barrels. Unlike Brit aircraft, which used doped canvas patches, I believe these 'caps' were carboard or some sort of wax plug, obviously shot away when the guns fired.
Really is the best you've done so far mate, and I agree with Dan, you'te improving rapidly.