[Arran]

I had a look at the dial and chassis of that Northern Electric, and the pointers are identical to your set and Art Hoch's, the dial is a bit different. Part of one of the dial scales on mine is rubbed away somewhat, it's that light blue colour like the police band on yours, so that makes me think it may be a "washaway" dial, so ask Art what he used to clean his with. However it does not not seem to have as many bands, maybe the longwave band was omitted on my model? Anyhow I think that the vernier scale pointer is just pressed on, I could not see a set screw from the back side, you may have to wraps some string around the hub to gain some purchase to pull it off, the center pointed seems to be held on in the center of it's shaft with a screw.
Regards
Arran