Neil,
I have a fillet gauge for you. It's by FibreMetal, measures 1/8 to 1 inch, concave and convex, with metric equivalents. If that will work, send me a pm with your address. Nothing in your trading stock I need right now, but keep me in mind if you bump into any small (1/2 shank or under) end mills or keyway cutters. Don't sweat it though, the gauge was a garage sale pickup and for what welding I do, I'd be better off with one that measured whether the weld was one turkey....uh..dropping or two, so you're welcome to it.