Wow Talk about a thread full of non-sense.
1. the firing pin safety was invented by Colt in the 20's. It was only on a few guns before it what put on the shelf. Then in the early 80s Colt improved the line with a solid bushing, some changes to the barrel, and the FP safety returned. The main reason for the FP safety was a number of LEO and other contract proposals required a drop safety. Which is why SIG, Glock, Beretta, S&W, and others have them. There were no big gun grabbing law suits in 1983.
And for the so claimed purist, the only pure examply you can buy new is the Colt 1911 repo. Anyone running a beaver tail, novak sights, anything than a plain jane safety, Stippled / serrations and then squalks about a firing pin safety is a hypocrite.
2. Drop in barrel. You can get a drop in barrel that is safe and works just fine. But you may not get any better accuracy, it all depends on how close to spec your pistol is. A semi-fit is a diffent story and must be fitted. Thousands of thousands of GI 1911 and A1's got field replacement barrels that were never fitted. They just might not have the best lockup.
3. Drop in grip safetys work on some but SA does not cut the tangs to spec so I would not bother. Even on a Colt, the look is subjective.
4 You can drop in a trigger and there are sear and hammer drop ins that a novice can do but grip and thumb safetys need fitted.
This is a good source for do it yourself..
www.blindhogg.com/gunsmithing.html