This is just a quick and easy modification of one of those cheap self cocking pistols. It worked out rather well and I thought that I should share the info since it might encourage others to do the same. Im not a great shot with a pistol so I wanted to add a stock to make a sort of carbine.
I trimmed off the cocking hook at about 60mm from the end and filed it into a rough conical shape. A short length of 25mm aluminium tube was attached over this with a self tapping screw which is fitted concentric with the end cap. This pulls the tube up nice and firm but the real strength comes from filling any dead space with metal loaded epoxy. Additional epoxy was used to blend the tube into the body of the grip. The stock was made up with a neat fitting length of aluminium tube with a simple plate butt fitted. A small knurled screw fitted on the right side of the body retains the butt. Some satin black paint hides a lot of sins. It was necessary to reverse the rear sight so that it was further away from my eye and easier to focus on whilst aiming.
The finished item is much easier to cock with the new stock and can be converted between pistol and carbine in seconds.