Sig bought the rights for this airplane when he bought Berkeley from Duke Fox in the early 60's. I am using the original Berkeley plans with an updated instruction sheet to cover the updated construction. The fuselage has been beefed up with doublers, maple motor mounts, basswood caps and by eliminating that big hole for the wing to pass through with just a hole for the spar to pass through. It also uses the fuselage and the tip ribs to make a jig for building a straight wing. It actually builds a lot faster than I expected an I beam wing could be done.