Not wanting to modify the No4 one iota, and I didn't like the look of the current mount offerings, so I spent a while with vernier and CAD and designed my own solution and spent a few hours on the mill and with a bit of test fitting now have a prototype scope mount that can be swapped with the rear sight in a round two minutes.
Its not for the purists as its a modern scope, But I like the way it looks and its competitive, as it was top No4 in the club comp, beating all the No4T's that were present, so well happy.