A true modern 1911 will be fully interchangable with the original 1911.
So.......if a pistol has Bomar sights, it's not a true 1911? If a pistol has a fitted beavertail it's not a true 1911?
Oh, wait...... if a pistol has scallops behind the trigger.........it's not a true 1911! If it has a short trigger, it's not a true 1911! Those were M1911A1s, right?
What about the pistols made in the years after 1911? Were they 1912s, 1913s, and such? After all, they were not made in 1911!
The fact is, with the S&W 1911, all parts are interchangeable with other modern 1911s and swap out with the standard 1911 parts on the market such as Ed Brown, McCormick, Wilson Combat, etc.., except for the external extractor. That is what the original poster was inquiring about, not what other people's opinions of what constitutes a 1911 are.
Here is a 1911 not made by Colt.