Jim W
·Several watchmakers who frequently work on vintage Seikos routinely improve the appearance of oxidized markers and hands. I don't know exactly how they do it, whether it is just gentle cleaning, polishing, some sort of treatment ... I'm not sure. But I have firsthand experience with some very unexpected and welcome results. It's really nice when I buy a watch thinking that the hands and markers aren't great, but I can live with them, and then the watch comes back from a service with clean markers and hands.
Regarding the moldy lume that @Jim W mentioned, Spencer Klein frequently mentions a product that he uses to restore the lume to its original color. The videos are extremely impressive, but it seems to be something proprietary because I don't really know anyone else who does it, and obviously I have no idea if it is a permanent solution.
I think it depends on the kind of lume. Patina is one thing, and can be quite nice, mould is another thing altogether. It is what it is, mould, It has no place on the dial of a watch of mine. I doubt it is an issue with modern lume.
I have owned 12 62mas over the years, and most of them have been relumed at some time. The best way to tell if a 62mas has original lume is to look for mould. if there's no mould then the lume is probably not original.