I'm guessing he meant put saddle foam on the edge of the fuse that contacts the wing to give it a bettter fit and not have an abrasive rub.

On my lazy p51 I had to put 2 thickness of foam on one side and 1 lawer on the other side to help make the rudder/fin more 90 degree angle as it built a little off.

I love my plane 18 flights before flutter became a problem on the elevators and Im trying to find time to replace the rudder dowel/thin wire with 2/56 run through tubes.

BTW the lazy 51 is my trainer.

My other complaint is the grey covering hard to see a a distance.

Going to recover when I can with easy to see colors, white yellow red ect.

Good luck with yours, Dennis