Ok I will say this and its my opinion but if a person wants to try to do something they should and learn from thier mistakes.  I am no gunsmith but I can swap parts and have put together a 1911 or two from Caspian with the machine work done.  Kart makes EZ fit barrels.  Back when I was in the military one of my guns said they were "building" a 1911 with drop in parts and I told him there is no such animal.  I looked at the site and has a lot of good information.  I would not try machine work but some parts can be done with hand tools.  As I recall my Chief told me I could take more metal off but its a pain to put back on.  And work on the less expensive part whenever possible.