There are no such thing as a drop in part on a 1911. The safety would need to be fitted, or at least ensure that the sear does not move once cut on and trigger is pulled. You ease the hammer back and listen for the sear to partially reengauge from the slight movement. The fitting of the tab on the safety that blocks the sear in position is a true precision fit. You need to know what angles to file and when to stop cutting agressive and start polishing for better words. It is easily cut too much and then a scrap part, one swipe with a 6 or 8 inch mill smooth or finer file can be too much. You would need to know you are getting close. Look at this link for an idea.
http://forums.1911forum.com/showthread.php?t=376137I would grind exterior off the right side before fitting another one if I were you. Either that or pay someone to do it that has experience with the platform. Before I was taught how to build I screwed up two while looking at the one I took out as a guide to show where to file and how much. They aint a glock
