Riveting new top right elevator skin to spar. Reordered counterbalance ribs and skin. too much plastic protector covering too close to holes being riveted makes it impossible to get a flush rivet using a back rivet plate?? Using short bucking bar and blind feel to set rivets. much better results even though its a REAL PAIN. Only one hole had to be Oops Riveted (had to drill out this one once also).