I've converted a few planes to bolt on. What I did was drill two 1/4 inch holes in the leading edge about 1.5 or 2 inches either side of center depending on how wide the fuse is. Glue 1/4 dowels so that they stick out 1/2 or so. Mark the spots on the former and drill 1/4 holes. The former has to be ply and strong enough to hold good. On the rear of the wing glue two hard wood blocks to the inside of the fuse and drill through the wing and into the blocks. Tap the holes in the blocks 10 -24 or 1/4 - 20 and enlarge the holes in the wing for nylon bolts.