Thanks I’ll pass this info along to the interested buyer, I appreciate your help. This is the pic I posted on the offering site. I unscrewed the screw shown in the pic but could only manage to accomplish a very slight gap between the arm and shell and grew nervous about pushing past the point of resistance.
https://www.ebay.com/itm/143485590169?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649
https://www.ebay.com/itm/143485590169?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649