I was talking with Youxin and said he only ran acetone on the black paint because it is lacquer and will not be affected by the acetone. He did say that the white paint used to fill in the engravings is enamel and would be affected by acetone, so he did not touch that with acetone. My black paint M4 is from 1969. Is he correct about black paint M4's being Lacquer and not affected by acetone?