Is it an early AF? Later paints are much more likely to be immune.
It really is a gentle product, but those early paints could even be water based.
The paint industry had a move to much better products as a whole.
If I hadn't soaked overnight, it would have likely been fine.
I was repainting anyhow, the rust was very deep on the M-10000 set.
The six inchers were average in the rust dept. But soaked hours.
If it has paint on the inside you might try it there.