After leaving it in acetone overnight to no avail and wasting money on a couple of thoroughly benign paint strippers, I applied elbow grease and eventually managed to strip the powder coating off the front fender bracket. I then sanded it with WD40 and three different grades of sandpaper, finishing off with a few dabs of Mothers Mag & Aluminum Polish and a 6" buffing wheel attached to my drill press. (The cheap Amazon buffing wheel sent fibers flying all over my kitchen, the downside of having a drill press in your kitchen.) I won't be putting it back on the bike until I've finished taking the forks off, drilling a few 8mm holes in the damper rods, and installing the YSS upgrade kit.