Vz 58
I have one and really like it over my Yugoslavian AK. It feels smaller but functions really well. I heard the 858's had some problems but it could be BS. It feels really great with the normal stock but the folder just doesn't do anything for me. I feel it is going to slip off my shoulder; I might try some tape with a rubber texture like on a Pachmyer grip.
I just thought of something I have a friend that sells Spongy Wonder Bike Seats and he uses a really great sponge material that sticks to his seats. It would be great for the folder, offering recoil protection, grip, and extending the stock. I helped him develop the frames and he holds the patent for it and Dragon Fly Footballs. If you are a person that likes to bike, they offer less stress on your tale bone, unlike other bicycle seats. I am going to ask him for some samples and see what I can do with it. If anyone is interested in some of the material let me know and I may be able to snag some of the material for you.