i'm trying to figure this out too? just bot a pair of the 07/08 dumonts, and plan on mounting them "true center" If i take a tape measure and lay it on the tip of the ski, it doesnt seem like it'll be super accurate since the tape measure doesnt really bend because it's metal. Any advice on finding true center? and lastly what are these "DARK LINES" you speak of? sorry to be so picky, i need all the help i can get!