After looking at the parts for my pneumatic sqeezer for some time, I am quite certain that the set holder is bent. It's very difficult to see it with the naked eye, so what I did was to take the part and insert it into my drill press. Then I spun the part like you would on a lathe. At high revolution, I could see the wobbling of the piece, indicating the bend. When I spun the threaded portion of the adjustable set holder in the same manner, there was no wobbling visible. While I could potentially order just the bent part, I am electing to purchase a whole new assembly at Oshkosh Airventure this year. I'll probably get a rivet drill-out tool also so I can dismantle the work to fix or replace the spar skin... :( Bummer..
