In one of the SPARC talk videos I think someone asked who makes the Rebco film, and the speaker said there were a handful of small companies around the world.

In one of the SPARC talk videos I think someone asked who makes the Rebco film, and the speaker said there were a handful of small companies around the world. I don't remember if he was any more specific than that, but anyways it seems it's kind of a novelty low-volume product at this point. I assume with demand picking up that manufacturing capacity is going to grow along with it. Low temperature superconductors in general is, of course, an active area of research. There may be better alternatives to Rebco just waiting to be discovered.