My first question is, is there a converter with 40mm guidance "plug" and splines to fit a 22mm axel?
Second: Is the "plug" massive? can i "grind" it down to 40mm?
A converter that has the small hub that fits your crankshaft and that will fit into a later transmission would have to be custom made. I'm not a transmission expert but don't think a large hub converter can be turned to fit a smaller hub crankshaft. The crank could be turned to accept your new converter though. Hope this provides some assistance.