As I mentioned in my earlier post. Draw a vertical centerline on the firewall.

Block up the wing so it's level then put the fuselage on it and square up the line on the firewall to the workbench. That will give you a good starting point. Shim the wing as necessary (or work on the saddles) to get the wing sitting in the saddle so that relationship is right. Now add the stab and square it up.

What you need to do is find a reference point on the fuselage that you consider to be "right." A man with five reference lines never knows which one is straight.