... it has to be the bezel. That was really fat with the old Panoinverse, now it's very thin. Perhaps that is enough to create the optical effects I was describing. Then the outer diameter and caliber would be constant. Perhaps he can confirm.
... that could fail of course. But the pictures of older model show the compactness of the dial, distances from the outer dial edge were smaller. That is a fact. Now... if it WAS 42 in the olden days, then GO would have altered the movement to get the new look. And I doubt that.