If you'd put a piece of .45 brass in the ejection port as if smokestacked, or a piece of 1/2" dowel or something, you might have found that bushing a lot easier to turn when reassembling (or disassembling). This is because with the barrel now out of battery, it's now lined up with the bushing, and not stressing it vertically in any way.
If the bare bushing (no barrel) is still hella hard to turn in the slide, what I'd personally do is lube it up with Kroil or something and (put the slide in a padded vise if necessary) and sit there and turn the bushing back and forth with the wrench until it got reasonably easy to do (though NOT loose). At that point I'd clean out the oil and loose metal and probably find a very pleasant fit.
Charlie, with his superior skill, big brain, and professional tools, might have other advice, but that's what I'd do at this point.
