1A stem of unknown vintage but 26.4mm clamp, so pre-mid 90s. Has the alloy expander bolt and wedge. Is it safe? It doesn't look damaged, the hex head is undistorted and the threads are excellent. I don't think it's been overtightened. Does anyone know the correct torque? I'd guess less than 5Nm.
Should I improve the odds by polishing it or (a tip I've read elsewhere) "setting" the wedge with a steel expander, if I can find one to fit, then replacing with the alloy bolt?