Turning crank journal down for 2.10 rods

In terms of cost effectiveness - It will need the grinding and finishing. Given the amount plus adding a new radius and widening that's not a typical $300 turn and polish. After that IMO it should be re-nitrided. I'm not sure on that cost. But i'd get some prices and see. A new crank might be less once you consider everything vs selling what you have without modifying it.