I think the number 10 drill was made before the 510. It had an enlarged seedbox but not as many bushels as the 510. Seemed to be built with a little heavier looking but narrower bracing on the hitch. I remember seeing, "Made in Canada" on them when new. I think Hamilton, like was mentioned on an earlier post, was where all drills and most field cultivators and chisel plows were built at least shortly before the end of I H and probably alot earlier. I H drills had by far the major market share of drills in our area where John Deere is strong.