I think I’d grind down the nub, drill and tap for a slightly smaller piece of thread stock, then backfill the handle (might have to drill that out and plug it?), then drill and tap the handle/plug for the thread stock. Basically tap both pieces for matching male threads and join them with said thread stock. 

Ryan/// ~sigh~ I blew up another bowl. Moke told me "I made the inside bigger than the outside".