I think I have it covered.

I removed the LMO and examined it ... there are two pins, one of which acts
as a stop for the disks / collars for travel in both directions ...
clockwise and counterclockwise. The other pin was extended out enough to
engage one of the collars prematurely ... before the tab hit the other pin.

I tapped the wayward pin back a bit .. away fom the rotating tabs, and now
the last tab contacts the first (left, as you look at the LMO from the
shaft-side) pin properly and provides the requisite LMO travel.

I am a bit surprised that this "right" pin evidently shifted position, as it
didn't move back willingly.

My thanks to all on the newsgroup!

73,
Jeff