I merged a couple of your threads and posted the YouTube video that you were unable to post. I just wanted to make sure you heard it from me. Not censoring, just getting rid of duplciates and putting in the link you couldn't get.
I've been following the sprocket issue. My Dad worked for Equipment Services in Anchorage when they were the dealers and bought a new ST4. If I remember correctly they were re-facing the sprockets back then. Has anyone tried this approach? I have a friend here in Homer that owns a Propeller shop and they re-build boat propellers all day long. They weld new material on the edges and grind off the excess. There's a specialty welding rod site that might have the correct bronze. I'll check it out.