Wow Gary thats a rare one, just goes to show you can't go wrong with the 'if in doubt convert it to pipe keys and make a new curtain' principle ! I'm amazed Chubb done it on those though, and noticed its a proper brass curtain instead of those daft duralumin ones. Very nice lock though and looks to be in pristine condition.

Tom, theres a mating groove cut down the stump in order for them to bite.