Bob,
Now I see the problem, the right trailing edge is 1/4" lower than the rest of the wing (wash-in?). I missed that completely, too focused on the tail.
As for how it handled, with the Nelson venturi half closed it was still a handful. The faster it went the more right aileron I had to hold. Even on power off glide I held a lot. I will cut the right trailing edge as you described. Perhaps I should put it up 1/4" to match the rest of the wing?
Then as Combatpigg warned I will toothpick the wing tie downs to the fuselage sides. The weak landing gear mount is already history as we fly in a pasture and 'normal' landings are near impossible.
jaka analyzed the wing warp correctly also. Maybe I'll do the 1/8" step first. At 150mph it should make a whale of difference.
Thanks to all, I'll update next weekend how it went.
The Jett 6 oz SLIM bubble-jett drops perfectly inside. No lead needed to set the CG at 2-1/2", just the battery located approx. under the aileron servo. To lateral balance it took 3/4 oz of lead in the left wingtip.