I mounted my 5" vise back on the mill , so I could mill the key slot in the new input shaft on the neighbor's foundry blower . I found that the slot in the gear has worn to .139" , so that's how wide I milled the slot in the new shaft . Now I need to machine the outer end to match the ID of the crank handle and case harden the bearing surfaces . Next up will be boring the gear to match the new shaft (larger OD because the "bearings" are bored holes in the CI case ) then a new aluminum bronze bushing for the fan shaft . Then put it all back together and burn some coal !