Results so far.
Attachment 234948Attachment 234949
So into the walnut now, preloaded with ammonia free brass polish as per the box, but I've added some of the polishing ceramic, which was still saturated in metal polish from yesterday's session.
I will reserve judgement till the process is completed, but don't think this will eliminate initial sanding below the 400 grit range regardless of grit used. Just doesn't have the mass to really bear down against the grit to remove the real nasty stuff.