As I recall I got the plans from Jim Pepinos Scale Plans and Photo Service. After Jim passed his missus kept it running for several years and it was from her that I got my set of plans. She has sold the plan business and due to a computer crash some time ago I lost all my data on the site where the old Pepino plans could be sourced and I don't remember the name of the outfit that was doing it. My plans are prolly in good shape but as I mentioned above all my shop is packed for a move and it may be a few months before I can find them. The original plan had about a 3" square box in the core of the fuselage running mostly the length of it and I opened up the inside a LOT and lightened the central crutch as much as I could while fleshing out the shape with formers and stringers with the necessary sheeting at the front. .