A bit OT but it is interesting to note that the main purpose of the 2nd (1869) Stanton rebounding patent is often missed. If you look at the picture below, in a conversion from non-rebounding you will see that the sear spring would have to be sacrificed or moved to use the bottom arm of the main string to power the rebounding effect. The use of the patented main spring gets round this problem. Quite why it was used on the bar-lock pictured in The British Shotgun is beyond me other than the possibility it was specified in order to have the 'best and latest'!
