On a pair of legs to hand, the top of the leg passes through the top hole of a lamp bracket. Here the leg has parallel sides, and there is no restriction on movement. The marginal increase in diameter where the lower yoke fits is a good 35mm, top to bottom, more than the thickness of the lower yoke clamps, so scope for up or down variance, the critical part will be the distance between the yokes, a function of production variation, and to a degree the type and condition of the head bearings.
Finally the new headlamp brackets may not be quite right, but using original parts in my experience a nice snug fit is usually obtained. Worst case has been a tiny gap between the underside of the top yoke and the top edge of the shroud/headlamp bracket. Slotting the clamp holes in the shrouds fixed this....
Swarfy