The rod, typically, broke 7pm new years eve. Attempted superglue without success, then, without dowel screws, used a self taper into one half, cut the head off and screwed the other part onto it then ground the rough parts smooth with a modeling rotary tool. Worked very well but then hit by an inspiration, a 10mm bolt, the hex head fits the diaphram shoe exactly if a little proud. I used mild steel rather than stainless simply because it was easier ti drill the hole but I would still expect it to last a considerable time.
Isle of Wight, December 2012