Don
I have also have welded a few couplers,I had one with a good amount of wobble, ended up boring it out sleeving it with 17-4 then welded it all up. After that I bored a ne hole and drilled the spring pin hole. The 17-4 got a bit hard after welding, so drilling was a pure joy. Not so sure it was worth all the effort but was a reason to use lathe and mill.