Wooden mudguards

Right, by compound curve to you mean along two planes, not one? Too tricky perhaps.

Maybe sanding (or reaming or what have you) out a dipped section along the length then, once it's been laminted with a flat section. Maybe a bevel or step along the edges of the top would look ace with contrasted layers of wood?

27" rim jig probably a good idea, though the final product ought to have enough flex to allow fitting to diff wheel/tyre combos pretty easily. I don't know about the adhesive side of it but presumably one that doesn't harden too much will work.

Yeah, they'd come out with a little flex in 'em for sure, though they'd have a pretty strong "memory" to their first position, so if you wanted them hold at a different radius you'd need to support them there with mountings.

I'll start doing some research see if I can knock something up