Made the flap rib form blocks from some left over MDF. For small runs of parts, MDF works pretty good. I do hate working with it though because it's makes such a fine sawdust that gets everywhere. I made the cutting blocks from some left over 3/4" plywood I had laying around. I'm planning to get some of the good 7-ply birch stuff for the wing ribs. This looked good enough for these simple, straight-cut flap ribs though.
