Since it's a website showcase gun, it may not be important if it ever was delivered, only that it is representative. I wonder if it's just an oops, and a courtesy email would prompt them to relook at it and decide whether to leave the picture up or not. Maybe, they think it's okay like that.
Exactly. It's about their standards. I don't believe a head finisher or a factory manager at Boss, Purdey, or Holland & Holland would let such a gun pass final inspection. I've seen misaligned screws on guns by the London three, but these were used and pre-owned guns that would've been taken apart and serviced by gunsmiths during their lifetime.