Not only is the race curve unique, one hopes the surface is as well.
It's very rough; looks as though there hasn't been any attempt at improving the surface after it was stamped/forged, and if it was machined the metal sure didn't like it:




It's possible to do much better with a stamped cone - not sure what mfr this is, was in the drawer of pulls:



And when you see a ground-and-polished cone - even a pull - there is another world of difference.