As I learned as a young toolmaker, there's always more than one way to do a job, but my thought is a couple thousandths would be too much and split the aluminum at the thinnest point.
Without the dimensions of the hole location, it could in some cases be difficult to find exact center unless you have a un-damaged part to use for location purposes. If the original hole was close to 50% undamaged, it would be easier to pick up it's location. I'd plunge the closest sized cutter I have into the projected center of the original hole. I would make both rail bushings based on the size it would take to keep as much of the original material as possible as they wouldn't have to be the same size on the 0.D., only on the I.D. Once I had a perfect hole, I'd make the bushing a half thou (.0005") larger 0.D. and push it in with the arbor press. The smaller number wouldn't put so much pressure on the remaining material as the 2 thousandths press fit and since there's no rotation on that part, it would hold up over time.
If you come to a point where you need to do something, reach out to me and I'd be happy to do some for you. I'm not really far away from your area, N.E. Shiawassee Co.