I looked again this morning. The dowl must be a cross brace for the wing assembly. but where the wing join together there are no markings of any kind as to where to cut the hole for the cross brace. There is a single dowl for the leading edge. It is attached to a peice of balsa that appears to get epoxied between the wings when you join them together. The is also a strip of fiberglass cloth about an inch wide and probably 20 inches long, It was in that bag with the balsa used for reinforcing the wing mount bolt section. I assume this cloth is applied the to seem once the wings are joined and exopied to give additional strength? Skyhawk are you there?