Singlemalt, you got lucky using steel wool on or near a Wenge neck/fingerboard. Warwick has long said that is a 'no-no' due to the tiny holes in Wenge. If any tiny pieces of the steel wool get into those holes, you won't know it until you get bloody fingers. The Scotch Pad should do most of the work I'd think.
French Tip (white) nail polish dabbed onto the existing side markers. Comes off with nail polish remover and you will see it.
Been on my bass for more than five years and shows no sign of fading.
Probably under $2 at the dollar store.
Fishheadjoe