I've used EverBright metal polish wading and it had worked well, without any damage to clean dials (as well as all exterior surfaces of DIs).
The solvents in the wading cut the grime with a minimum of liquid involved. Then buff surfaces dry with a clean soft cloth.
Use EverBright on the lens also to clean it. Then microabrasive film (start with 15-12 micron, and progressively finer) or headlight refurbish kit to polish the scratches out.
YMMV
EDIT: I just remembered that I had one indicator face that developed black streaks when I cleaned it. I think there were microscopic particles of graphite in there (maybe somebody had used a lock lubricant). Anyway, I rubbed with a soft vinyl drafting eraser (white in color) to remove those streaks. Worked a treat!