The 1911 is the greatest of hobby handguns because everything is fitted. It's all about the love. Even if your manufacturer sells the part, it's going to need inspection and likely a little tweak. Higher quality 3rd party (non MIM) will require a fit. Plenty of smiths around that can provide you the service.
It look like it will be a gunsmith job. I got my parts in the mail today. The bushing if a near perfect on the barrel, but is way tight for the slide. I could probably force it in, but would never get it back out again. It looks like it will need fitting. It's about a blonde hair too tight.