i don't think it should be that long as most guys buying such things want big name behind them. i would think a guy that orders one would have to worth a lot more $ then purdey or holland patron.
there was one american industrialist that ordered pair of atkin guns because he could get top quality for less cash, but he was already so wealthy he didn't give a shit what anyone thought of his stuff. for him there was no need to shoot top name gun as he already had everything.
PS. This is not under one roof deal like: H&H, Purdey, WR,..... it's just several craftsmen screwing guns together and engraving name Boswell on final product. There is no way one could support entire gun company making just six guns per year.