When it comes to making the square stock that fits over your handle . I was able to find a company that sells this stock . If comes in two or three inch lengths and only 1/2 inch diameter . I was able to machine down a piece of pipe with inside diameter 1/2 inch and outside diameter I had to machine down to look like the original part with a 'c' clip grove for reassembly . Once it was machined down I merely welded the square hole shaft to the new piece of pipe already machined down . The picture below is what the part I machined looks like that fits over the square holed shaft looks like . Again can also be done on drill press if patient . If having trouble email he at
srpenner@hotmail.com