Hello Ty,
The fuselage has carbon built in. The aft portion of the fuselage is a truss structure. The top and bottom long-runs were made by sandwiching a .007 x 1/2 in carbon strip between two 3/16 balsa strips.
The two Cardinals I had were very flimsy in the rear so when I decided to build these I wanted to at least cut some of that down. After laminating the fuselage with the 1/64 ply I was very pleased with the result. The fuselages are very, very rigid. I saw the picture you posted showing the fuselage twist you are experiencing. I'm going to try and get a shot of mine like that and see if I really did manage to all but eliminate the twisting.
The wing is built nothing like the original Tutor. It is stretched like Jim Armour did his but the structure is more like a Trivial Pursuit wing. It is very rigid also. I am going to try and knock off a couple ounces on the second wing. As strong as this wing is I believe I can lighten it up here and there and not compromise any strength.
Clay