Here's some things I did to my Colt Government XSE;
I hate plastic! Everyone here knows that so I guess it isn't a surprise the first thing I did was to remove the composite mainspring housing!
I know, I know, most modern era 1911 owners don't even know that their MSH is plastic but I did and it needed to go!
I'm a high-ride grip freak and need my strong side hand up as high as possible on the grip. A flat, back-strap gave me the only reason I needed to change out the tupperware. My choice was a Smith & Alexander arched MSH with Mag-Guide. This arched MSH forces your hand up and into the beavertail, or in this case, the lousy duck bill grip safety on most Colts. I have had experience with S&A when I replaced the same part on my Defender and their quality and customer service is top rate! If you have a question about installation, give Alan Smith a call, he will walk you through the process until it's working! A conversation with Alan is like a pistolsmith lesson. Barbra Smith is equally knowledgeable and both are a pleasure to deal with!
Smith & Alexander - "The Mag-Guide People"
I got the government model arched stainless w/mag-guide; Model # GMAS MG for $78.95.
Installation is simple and the only extra step required is to install the spring and caps from the old MSH. (No sweat if you have a Wheeler Bench Block!)
While I had the gun apart I replaced both the main spring and the sear spring.
I went with the Wilson Combat Bullet Proof®
Sear Spring P/N 417 for $6.95.
Bullet Proof Sear Spring
And I opted for the Wilson Combat Mainspring (Hammer Spring) "Reduced Power"
P/N 27 for $2.95. This spring replacement results in a lighter trigger pull. The hammer is easier to cock by hand and while cycling which should improve ejection reliability.
Mainspring (Hammer Spring) Reduced-Power
Needing a pair of 'MagWell' cut grips I found these real stags from Argentina on ebay for $55.00.