The final reduction gears on the right side of my Yanmar compact tractor are damaged and I have not been able to find replacements. The 3" dia. straight cut pinion has half a tooth broken and the next tooth has a crack in half of it. The mating 12" gear has minor damage in 8 to 12 teeth from meshing with the broken pinion. Can these be welded up and recut? Any suggested sources? Thanks, Bill.