Re-levelled the fuselage and used a digital level rather than the cheap builders level that we tried yesterday. Got the incidence right, and applied a mini G-clamp on the wing spar resting on the fuselage root bracket to prevent the wing drooping. Then used a ratchet starp to pull the wing to symmetrical 'sweep' Checked with multiple measurements and accurate to 1mm at the tips. Found a washer that had exactly the correct radius to match minimum edge distance, and claped it with a 1cm spacer to the spar prior to drilling. Checked alignment again, and sweep again, then drilled SB side. Edge distances all ok! Checked measurements and the drilled port side. Again, measurements all ok. Relief!