British Pre WW2 helmet help/advice needed

[browningautorifle]

it seems impossible to take one layer of paint off without at least altering the color underneath it.

I have a Mk3 helmet I picked up from overseas and brought home 45 years back, had a national flag on the side that was painted over. I wanted to confirm what flag and carefully used some acetone and a rag. I dabbed just at the one spot to eventually expose the flag, that was all I removed. The rest would have been pointless, it would have been UK olive covered by Greek truck paint.