I put sharpie on Akzo all the time and it comes off no problem with acetone. I also use the same on bare metal. But on painted parts, I've actually had good luck just rubbing my finger (alot) on the sharpie mark, but in truth, that wasnt on clear coat so YMMV.....
MustangII (FoldingWing) "Finishing up": IO360B1E,RSA,C2YR-BF/F7666-2,Superior sump,James; 2xHXr,MiniX,EIS,480,327,240,SL30,Navworx; SteamAlt,AS,VSI,wet compass
Don't be a hater; I'm a cousin with thin wings!