Quoted:
Honestly brother I went the same route 12-14 years ago, you may want to consider returning your colt to the almost stock condition you have in the first photo and keep your aim point & rear sight.

If you really want to modify a carbine, just get another rifle to modify and have fun with it.  for a duty weapon the less is better. You probably already know our chiefs & administrative types don't know crap about weapons on average. If you're unfortunate enough to ventilate a bad guy with your rifle remember it'll be on display in front of 12 people not smart enough to get out of jury duty. I wouldn't want mine looking like a Star Wars blaster.  

But times are good for buying a second rifle and mod it all you want, shoot some two gun matches or whatever.
If your close to Jackson or Corinth I'm teaching a carbine class in the next couple weeks. IM me if your interested.
I promise you'll be ready to ditch that rail.

These guys are offering some well meaning advice, but keep in mind we live in a different world now days.