I would think the right machinist could make one, as long as he had the pin gauge necessary to check progress.
It won't be cheap.
1/2" OD with your specified ID would make for some thin walls.
Possibly too thin.?
Seems it would need to be sleeved before the ID was cut, but with CNC mills who knows what's possible.
Might need a larger OD bushing and die body to hold it.?