I had no idea, it seems to be a big secret as I can't find any reference to them even on the Schmetz website itself!
There's not a huge range but
here they are on the Ironing Press Company website who also have a good range of Schmetz needles including the illusive Schmetz Superstretch (labelled just as HAxISP). I'm very happy with the Organ superstretch which I can get locally and about 50p cheaper so I'll stick with those but it's good to know the Schmetz ones are available somewhere here.
The scissors seem a reasonable price so if I hadn't just got some Ginghers I would have given them a try to see if they live up to their brand name.