I found a good used one, which is right now on it's way to me. I didn't spot that Kelvedon have them - so thanks for pointing that out. The photo on Kelvedon's website shows an arm made from a flat piece welded along it's length to the side pieces. The original is a single piece of steel that is (I supposed) pressed into shape, with welding just for the inner end and damper mounting tube. I'm inclined to think the original pressed style is better if you can get them.