It looks like someone tried to clean the machine with turpintine or another strong chemical, because you can see a smear of gold across the black paint.
It was probably alcohol, which dissolves pretty much everything coating the cast iron. That be a warnin'!
To get rid of the excess, I would use car cutting compound. It's a very, very gentle way to remove a thin layer of paint (or whatever). The harder you rub, the more paint it takes off.
Use (obviously) only with a very clean, soft cotton. Read the instructions, too. Sometimes the manufacturer recommends wetting the cloth first.