OK - long past time to revisit this thread - I ended up buying a parts gun for the bolt I needed. So great to have my old '72a back in service. It is one of the favorites for the grandkids to shoot at the range, and with bolt action, they don't burn thru rounds so fast.
However, I will always be on the lookout for a viable Winchester 72a bolt assembly, even one with a broken handle.
I am continually monitoring the parts sites, but this is a popular needed item, as the handle is prone to breaking at the threads and can be repaired, but often wasn't.
So, any ideas folks are appreciated.