Patrick writes:
Spring steel is a lot hard to work with and pratically impossible to fold without breaking it. I know that I can buy those parts somewhere for peanuts but where? If you have ever heard something about that king of fasteners and if you have the time to answer me, please let me know where I can find that kind of parts or how to make it efficiently.

Added above are sketches of what we can obtain here in Germany at a Hang Glider manufacturer/supplier. Does anybody have an address of a supplier in the USA or Canada? The German address is here, but doesn't show the parts anymore. Maybe they are in their paper catalogue.