Just by way of an update: Wefco Rubber still has replacement rubrail parts. Track/channel is now rubber rather than the original rigid PVC. $5 per foot for the channel/track, a bit less for the insert. Black and gray available. And Pete is still there dispensing terrific advice. Shortly after replacing the insert, I tangled with a pylon coming out of a slip in Fisherman’s Bay, Lopez Island, in a strong flood current. Should have listened to my wife who advised me to keep a line on the dock cleat. 40-year-old PVC shattered, so now I am doing the track.