I'd need to know more to be certain, yet I suspect that the adjustment hex screw is the one underneath. I suspect that the top one is just a dust cap.
I'd want to find out for sure before trying to do any more work on it.

EDIT: so the minor gap doesn't look right if it was taking any load at all but I don't think that it is taking any load at all, not withstanding that once the stem clamp is tightened up, these adjustment screws never take any load anyway. You only use them to get the bearing tightness just right, which isn't much at all and then you tighten the stem bolts. Of course the stem bolts have to be loose to effect any adjustment in the first place.