I'm hoping one of the grey-beards here can help out.
I sold a 1902 monitor and during transit it was subject to a magnetic field which has left discolorations.
Does the 1902 self-degauss? Is there some magical way to degauss these for the home gamer?
It should degauss itself over time, but you can also use a soldering gun (not pencil). Hold it near the screen and press the trigger, move it around and you will colour bands on the screen, move it away before you release the trigger. Repeat as needed :-).