Loads of people(and often people who weren't politically active much before, or had been anywhere TankTown) ditched their license fee in 2014 and had an interest in RT because it backed Yes. That was like building a waterslide into that territory. Wooosh!
As for asking if they are left, I don't see Red-brown stuff as left at all, but I suppose the name helps us understand what it is that is being talked about IFYSWIM. I don't think the Scot nats that are always on about the BBC/MSM etc etc are distinctly right wing when being compared to anyone else being discussed on this thread, if that's what you are asking. All these people talked about social justice, austerity, internationalism and all that sort of thing during the ref- so would right-wing help as a descriptor? Both terms seem simplistic and don't cover it really. Sorry if all that was clear as mud.