I have a pre-ban ar15 M4 style rifle, it's built on a COLT pre-ban lower, it's the old style A1 lower, my question is, would bushmaster be willing to replace my colt lower with a bushmaster lower and just copy the serial numbers, i really hate having an A1 style lower, on the other hand, i really hate destroying a colt green label government model, especially since i have all the original parts.

what do you think.?

Why don't you just sell it and buy the one you want.  That way you can get your rifle as you desire but not destroy something that someone else might find preferable.

Easy, next question? [:D]

I thought of just selling it, but the problem is, i need to find a pre-ban bushmaster before i sell it, a perfect situation for me would be, someone who has a pre-ban bushmaster lower plus cash for my colt, but that's hard to find.

There are alot of good pre ban receivers with push pin take down and fence.SGW,Bushmaster,Olympic,PWA.You can probably sell your Colt and buy one of the others and still come out ahead.