I've made a few tenors, and just make them like small Classicals. Scale the wood thickness according to the size: I make tenor tops, backs, and sides, about 70% as thick as I would for the same wood on a Classical guitar. A bari would want to be a bit heavier than that. With such a small soundboard I use five fans instead of seven, with two cutoffs, as per the usual Torres style. The besetting sin of most production ukes is that they're over built. With such small surfaces they can be made quite thin and remain stiff enough.