Rok Hunter
I am building a second GB300 from the Balsa Work Bench short kit and just finished the wing.
I used 1/2" square balsa inserted into the cut outs on the wing ribs leading edges. I then butted the wing sheeting up to the square leading edge. It was a pita getting it to curve and keeping the joint tight against the leading edge while the glue dried though.

I then used the supplied laser cut end cap for the tip as a guide for the LE shape. Rough shaped the leading edge with a small razor plane and sanded it to final shape with a 12" sanding bar. The razor plane makes quick work of it. I had about 20 minutes total time in each LE.

I took some good pictures of all this. It will not let me post them due to the sites minimum 10 post count not being reached yet. Sorry