[Arran]

You could try a strong trisodium phosphate solution, with hot water, but make sure that you have a hair dryer or heat gun handy to dry it after you rinse it off. You could also try household bleach like Bob did on the 38-62. If it is iron stains phosphoric acid will remove those, like the infamous black marks on top of consoles, but as soon as the stain is gone you need to wipe it off with a damp rag and dry it as well. I think that the front panel must be maple veneer so it likely thicker then average, so you may be able to remove much of it by hand sanding it if the chemicals don't cut it, start off at 120 grit, then 150, then 22) and so on.
What is interesting is that the stain didn't look nearly as bad until you stripped the finish off, even in the center section. It just shows the multitude of sin that tinted lacquer can hide even when it's flaking off.
Regards
Arran