An update. Yes, I FOUND my "gadget" just after I ordered a replacement! It was on my Lyman Xpress! I found it attached to the base and unscrewed it, the little threaded shaft had become affixed to the Xpress. I thought it was part of the Xpress. Got out the "jaws of death" (pliers) and gently unscrewed it from the base. The screw has a hex inset. Reattached the cutter head to the threaded shaft and gave it a good tighten. Found and fixed. Needed to trim some .223s and discovered my Lee shaft was slightly bent and presented a slight wobble. Now off to get another Lee .223 trim shaft.
