A friend has a .45 1911 that was custom made into a competition race gun. The bushing is not standard, but is a screw-in type, so it doesn't disassemble like the Govt. Model does.
How easy, or hard, is it to convert it back to its original configuration so its easier to disassemble and reassemble?
I've never heard of a screw in bushing. Only bushing I've ever seen or heard of are either the standard GI style bushings where you have to push and twist, or the captive one piece bull barrel bushings that you can just compress until they click into their compressed state and then push them a little to decompress them to but them back in the gun.
Then again I don't mess with race guns too awful much, so could be a competition specific thing.
Either way, my two cents would be to just leave it alone. Often race guns are so custom spec, that you'd spend more trying to convert it to a duty gun than it'd cost to just by a new gun. They're also made to MUCH tighter tolerances, which isn't actually a good thing for a duty gun. Contrary to what some may say, you WANT a little slop in your daily carry/duty gun because that little bit of play gives you variance in working conditions. if things are so tight that the slightest thing can put things off internally (like bumping it in your holster against a chair for example), then its not ideal for anything other than the range or competitions.
Either way, its not like standard 1911s are expensive. You can pick up a good ruger 1911 for like 600 plus tax so long as you're not trying to get the top of the line stuff.
I hear what you're saying about a certain degree of "slop"... it's a feature, not a bug, of most 1911's I've had over the years.
Pretty much, slightly different geometry, but its the same reason people who mess with their glocks too much actually end up making them LESS reliable than a factory OEM glock. Sure it'll TECHNICALLY be smoother and run better in controlled environments, but the tighter the tolerances you force on a gun, the less reliable it is outside of controlled environments. That's the reason glocks, AKs, etc. Have such absurd reliability. Because they've optimized the "slop" about as much as you can to get maximum reliability. 1911s and 2011s are more finnicky. They ALSO have some, but generally a tighter OEM. So when you get into competition and race gun tier 1911s and 2011s you're often dealing with nanometers of clearance levels tolerance, which is why they have to be oiled and lubed so often.
Hence, why your friend is better off just buying a new 1911 if he's wanting one for anything other than a range toy/competition gun
I will pass that along.