Typical early tornado issues were soft spots on the decks, esp. if balsa was used in the decks. Bent beams right at the bolt holes due to over torquing, distortions in the tramp track were the jib horse sliders have been prying on the tracks. Leaks along t he tramp track rivet holes.
I've got a 1980 SailCraft I'm trying to sell by the way.
Mike.