>>/62416/
pretty sure the black ring is the one that goes between the base of the fork and the lower headset bearing and the silver one goes on top of the upper headset bearing, I would be surprised if you can assemble the headset without both of them.
if you mean that there's a few (or a few too many) mm gap between fork and bottom of the headtube even after tightening the headset that does depend on tolerances but as long as you can eliminate all play when you tighten the headset it's just cosmetic