Picture 5 is VERY interesting Spike. It is a tapered dovetail patch as I mention in a recent thread about patching (Bren) butts. We had to do a few of them on butts and fore-ends as apprentices and they were a real pig to do - especially when you were really more interested in getting through the week to meet up with your girlfriend in Carlisle at the weekend! Useless (?) too as I never really understood what a tapered dovetail could do that a normal dovetail couldn't! Other Armourers thought the same as I never saw one outside in the real world. Then I do one to illustrate the art a couple of weeks ago then, lo and behold, see one for real today!