Next time, make a sheetmetal shield to keep the flame from hitting the sheeve. Then heat the shaft about an inch away until it is beyond cherry red for a while so some heat soaks thru the shaft under the sheeve. Now drop it in a bucket of cold water or quench it with a garden hose and tap the shaft out. If it doesn't work the first time, heat again a little longer.
If you keep scrapping parts that are becoming scarce, we may have to ban you from possessing them. In the meantime, I'll look and see if I have any extras. I think mine are all in sets.