On the Flusies which I have owned the bolt is adjustable. The round bolt passes through a square carrier with a set screw which can be loosened, the bolt slid forward for deeper engagement. The bolting surface itself is cut on a taper. The hinge is not adjustable on them & using this to bring the lever back to center does nothing at all except relocate the lever (unless of course the bolt was so worn the lever had reached its limit of travel). "IF" you in fact had bearing on the rib bolt moving the lever to the right will lose this bearing.
Arguments can be, & have, been made for the superiorty of both styles of bolts.
Some Crescent doubles had round bolts, at least a hammer double bearing the trade name of American Gun Co of mine has a round underbolt.
My favorite Double, the Lefever, has no underbolt at all.
