I had the machining done at a tool & die shop. They don't normally do car wheels but the owner did it for me at $100.00 CAD TOTAL for 4 wheels in his CNC machine. He didn't need to take the tire off so I didn't have to pay for un-mounting/mounting and balancing again. He cut to exactly 68mm so it fits the car perfectly.
My other option was a wheel shop that commonly does this kind of thing. They would have charged me $150.00 CAD TOTAL for 4 wheels for a lathe machine and they also would have to take the tire off which is extra $75.00 CAD TOTAL for 4 wheels to un-mount tire, re-mount, balance. So total at this place would have been $225.00 CAD TOTAL for 4 wheels.
Once I got them back I did 2 x prime, 3 or 4 x silver paint, 3 x clear coat to prevent rusting.
I think the balance is a bit off since they were balanced before they were machined. I will balance them next season.