Were fixtures for these lamps ever marketed in North America? I see GE/Thorn made some pretty cool adapters for them for the European market, but I've never seen fixture of any sort, or indeed the lamps themselves, here. I see you can purchase the lamps online, and GE does list the lamps in their North American CFL catalog.

I have a couple of dead 13 watt CFLs whose ballasts are still functional. Perhaps it would be interesting to get a hold of a lamp and socket, and convert one of them.