I worked on replacing the attach blocks. Made new blocks for left side. Bolted the wings together and marked the blocks one at a time .. then drilled them to 1/4 on the drill press. Matched up perfect. Spent some time discussing my approach with a friend who's built a Sonex before and another who's a machinist. I'm going to updrill to 3/8 the same way .. while the wings are off the plane and bolted together. That way I can confirm everything is straight as I go.