From what I've seen, a lot of the GC kits are pretty much the same, so when a shop local to me (in The Netherlands) started selling the kits for €2 each, I grabbed one. No lens adjustment, and have made one or two modifications as well (top headband from some velcro I had lying around, small nick taken out of the underside of the phone holder to accept my usb tether (Sony Xperia Z had side usb port), small bit of draught excluder strip to take the sharpness off the nose hole.
Apparently the only thing missing from the kit (as it wasn't supplied), is the generic 'button'.