I'm not sure how you can do that economically Norm , any machine work would be $10. then
postage is another $10.
It would be easier to go to a Auction, market ,scrap yard ,tip shop , tip ,garage sale ,swap meet,online sales and buy a complete Victa for $10.
Steven from this site was selling mower parts and would have the crank nut and posts out parts ,he is admin on the site.
https://www.facebook.com/groups/1638234439783704/about/The easiest way would be to send him a message as he had shed loads of parts.
The only other place I know of without buying a mower or trying a mower shop would be to ask on a Facebook mower group.
If Norm doesn't charge for lathe work, just cost and postage it's still more expensive than buying a complete mower.
Cheers
Max.