Colt for Colt - Value Change?

[Combloc]

If it were me, I'd keep the original upper intact and build an all new, all Colt upper to suit your needs.

I agree with outrider 1000%. NEVER EVER disassemble a collectible rifle beyond normal fieldstripping unless something breaks. Build or buy a different upper and don't molest the original. It was only built by Colt once.