FWIW, the fuselage of my first Cardinal arrived cracked just about the high-point of the wing. I braced it into correct alignment and drilled for 1/4" CF Arrowshafts aboupt 4" long, angled, top and bottom. After re-assembly, I added a couple of soft balsa plugs.
It flew quite well, until it's final appearance as a lawn dart. Inboard wing broke off at the fuselage, fuselage front end broke off (NOT at the site of the original fix), smithereened the Rev-Up (sob!) and the CG spinner and split the Tettra tank shell (repairable, I think).
Anyhow, the point of all this was to suggest arrowshafts as a repair medium.