These spots seem to come from a perfume which was added to models created between 1984 and 1987. The baby powder perfume apparently has affected the face vinyl so that pale green spots appear and spread across the face.
So far there has been found no way to remove the spots as they are deep within the vinyl itself.
It may be that other factors in the environment make the difference between a doll that develops spots and one that does not. Being in direct sunlight, being in damp conditions, or being in very hot conditions could make the situation worse as it adversely affects most vinyls.
These pale green spots are not the same as regular mold spots which vinyl and plastic dolls can develop. Regular mold spots are a darker green or black and should be treated quickly, and the doll put into isolation as the mold can spread to other dolls.
The standard treatment for regular mold is to first be sure that mold is causing the mark and not pen. If the mark is pen it might be removable with Magic Eraser.
A mold mark will be deep within the vinyl and not on the surface alone. If you apply pressure to the dark spot the vinyl will seem weaker and softer. If the doll is worth keeping and can be kept in isolation from other plastic and vinyl products, it should be taken apart and washed with dilute oxy10. This will kill bacteria and mold spores gently. Rinse thoroughly and dry thoroughly, then let it air for 24 hours.
When you are sure it's completely dry, gently brush the vinyl with talcum powder, be careful to avoid painted facial features.
Then brush off all talc particles carefully. This should ensure that it is entirely dry and can help halt the spread of the mold and prevent soft and sticky vinyl becoming worse.
Store the doll in a cool, dry area and check it's condition for worsening of the mold periodically.