I would think you can build up material as needed with welding, then size the hole again to fit the bearing. At least it is aluminum so the machine work isn't hard on the tools.
I have yet to take off my linkage so it may be in the same shape
unless you like replacing bearing every ride i'd say this is toasted. I'd get a new(er) one instead of wasting my time and money with a shop at this point.
02 KX 200 hybrid: RB head and carb
Sold ☹ DRZ 400 SM
You could fill it with Alumirod, Alumiweld, etc., redrill it to the right size, and install a new bearing and be good to go. Or, like Karl mentioned, a machine shop could probably bore and bush it.