[Translation of the original French comment]
I used to own one, which I had bought new, as a kit, from Bernard Danis in 77 or 78. Plans had been published in a DIY magazine, I might be able to find them again. The smaller version of the SK2 was the SK1. I have successively owned a Rithner Electra, an SK2, an Atlas, an Azur, hermes, F1 evolution, Exxtacy, and as tandem wings a Mouette 23, Lancer 4 and Medium. I have kept all Vol Libre issues since N.1, plus many other magazines like Finesse 10, Wings!, Hang Gliding magazine, Glider Rider, whole Air etc...
Well done for this huge database work! i am available to help on an irregular basis with all the hg literature I still have. Get in touch at the Coupe Icare or over the phone etc...