There are still potential solutions available, Paul. However, the first question is whether the home-made part I've sent works in the short term. If it does, it is "only" a materials and equipment issue to make a durable one. As you have reminded me elsewhere, I have been overlooking the possibility of using a piece of tool steel (extremely high-carbon, plain unalloyed steel) in a fully-hard, untempered condition. If there isn't much impact load, it could work.
