You really don't know until you have it in hand and remove the 'bad' bushing, then just try your reamer(s) in the hole and see if there is a good fit. Keep in mind that the previous repair person may have used a tapered broach instead of a reamer and/or made an oversize hole and punched or peened the bushing to keep it in place. You just play the cards in your hand and do what you have to do.
Getting a bushing perfectly centered is always a challenge and especially so when the original pivot hole has already been bushed. In spite of our best effort each bushing can potentially introduce an error, so all else being equal, a single bushing is more likely to be closer to center. The only time I use bushing in a bushing is when the only bushing that will fit the hole in the plate has an ID that is too large. I would knock out the bushing and hope the person who installed it centered the hole as a starting point. I use Bergeon bushings so if the first bushing is KWN, I can ream the hole for a tight fit Bergeon bushing.
