I have experienced the dowel issues on other aircraft. I ended up sliding some brass tubing over the dowels and epoxy them in place.Since the holes were already enlarged it made since to go this route. Just drill/file out the holes to fit the new diameter of the wing dowels/brass and my problems went away. I am currently building a H9 p-51 150 and did this mod during the wing construction, knowing the potential for dowel problems. Hope this helps.

Mike