Pedaled my Dahon Speed 8 to the Trek dealer's showroom/workshop on the other side of our neighborhood to get a replacement for a missing brake arm adjustment screw. No dice. Doubling back home, it occurred to me that I probably should check with our Egyptian plumber, who always keeps a cache of miscellaneous fasteners handy; he helpfully secured me a couple of near-exact matches (a couple of mms shorter than the original, but it still has plenty of range to adjust in and out.) No more of that tffffffffft tffffffffft tffffffffft as I roll around!