[Arran]

The dial lens is just a clear piece of flat glass, no paint or silvering on it, a glass shop should be able to whip one out in no time flat. It shouldn't be any problem freeing up the stuck controls, but it would be best to take them right apart so you can clean they properly and regrease the bushing around the shafts.
It's surprising how well that faux finish has held up, maybe it's the shear thickness of the clearcoat over top that saved it? I noticed that the grain they chose for the decal was quite elaborate, maybe over the top for a budget radio. It's supposed to be a stump walnut veneer with boxwood and zebrano inlay, it actually looks pretty convincing in a photo.
Regards
Arran