Hannes,
Thanks for the mandrel trick. It works. Had to whack a little harder than I was but was able to eject the mandrel out of the rivet. The nose ribs were still miserable because I could not hold the back side of the rivet. So, I have the skin opened back up.
I wonder if I can pop out the mandrels and drill from the back side. I don't need to get the rivets out of the hockey stick, just need to get the hockey stick off the forward spar.
Got a UPS notice that the new hockey stick is on the way. Still need to order some more angle, some more 3/4" square bar, and some more carbide drills.