I'm almost 100% sure that they are not Upside Down Synos. The photos are the ones of the syno in the tank with no substrate. One guy on Planet Catfish said that it could be a a young of a number of species.
Catfish_Dude, are you sure that your synos are Upside Down synos. If they look like mine they may not be. Just a thought.
Rob, I have seen these in Tropicl Blues (in Tirau), and the Jansens (in Silverdale, Hibiscus Coast). They may be in other shops too, but haven't been to any in the last coupl of weeks. They were labled as Faether Fins in both shops, also there nocturnal colouration is almost black. I will try to get some better pics.
Cheers, CatBrat.