Centerline is usually marked on the topsheet -- sometimes in the middle, sometimes towards the edge. If there is no other indication, then I would guess that UP arrow is the centerline.
The 9.00 and 4.1 numbers are the drill size to use when mounting bindings. 9.0mm deep and 4.1mm diameter (larger than most skis in width because it has a sheet of metal.)
The is the absolute only marking I can find...topsheet has nothing. The nordicas I have all have bumps at the center line on the topsheet.