According to Anderson et. al., this is the same plant as the previous post, just a representative of its variability. OK. I know they have their reasons, but I'm not convinced. I think I have a philosophical difference with them about the nature of the naming process. But that's another discussion. In the meantime I'll stick with the Sulcorebutia name and list the synonyms (including Rebutia canigueralii).
Enjoy your plants (even when you're not sure what name it should have)!