I swear this wing came off the board dead straight, covering is off and I need ideas on how to straighten this, it's 3 degrees up in the middle, tip and root are zero.
Looks like a case of **warped spar***. Can you put a straight edge on the spar top and bottom and have no gaps. In other words is the spar warped. TE's don't normally warp on their own without covering, but they will if the spar warps and the ribs push it down. What is the construction? If it is D-Tube and the front appears straight you are going to have to cut the ribs on one side to relieve the tension. Probably have to remove the T/E sheeting on one side. Do you cut your T/E planking from the same sheet so that it will have similar warp tendencies? Do you add spacers or cross braces to keep the T/E from warping? If not, now is the time. Let's hope it is not a deformed D-Tube. Is the LE straight? It is possible that it is bowed as well. Opposite if it is the spar, same if it is the LE planking.
If it is not D-Tube you have the joy of knowing that anything you do the TE will put pressure on the LE.
In either case you are going to have to relieve the pressure and replace anything that you have to bend to get into place. Jigs can be your downfall if you allow them to force warped wood into place.
I hope others have a better solution for you, but I have never been successful in removing a warped TE without surgery.
You can use heat but that is a whole-lotta-warp and unless you find the cause it will come back.
Ken
PS - you said that the covering was removed. Was it warped when you covered it? Was moisture or heat involved?