Hi John, that's what Schniederitis is - anti-reflective paint on the ground edges of elements coming adrift in tiny bubbles and then falling off as flakes.
Remove all the original paint first of course, I preferred to scrape it off rather than risk abrasives or wire brushes etc.
I've used different types of matt black paint, all were fine, not sure what Schnieder used (but it comes off so...)
An artist's rigger (long hair) brush I find is the easiest to use for this job.
Lightly press the element or cell with blu-tak to a slowly-rotating mount until it runs true, hold the brush steady - like on a potter's wheel.
Let all solvents fully evaporate before reassembly - a few days if possible.