Have you actually put a couple of incidence meters on the aircraft to confirm it is the tail that is out? You need to align the firewall so that it is exactly vertical and an incidence meter on the main wing and confirm that it is at zero. I set my Quickies on a table and brace it with those little rubber coated work out weights (thanks to the wife!)
so that it will remain straight. once the firewall is at zero and the main wing is at zero, you can confirm that the v-tail is at zero. If you use a standard incidence meter on the tails, you nee to make sure they are aligned perpendicular to the centerline of the fuselage (equal distance from the centerline at the front and back)
. You will need to check both sides, as on may be correct and the other one is not. The tails should both read zero. If any of these (main wing or v-tail halves) are off from the firewall, that is where to problem is.
If everything is at zero incidence, it is simply a CG issue. If you have the CG at 3" aft, I would move the CG forward to 2 7/8" and re-fly it. Most CG's on Quickies are in the 2 3/4"~2 7/8" CG range, and 3" is a little far aft for most. By shifting the CG forward, the elevators will not have to deflect downward to lift the tail heavy aircraft.
Hope that helps some!