The rail on any 1911 can cause holster fit issues. One of my 1911's is my primary carry, a Sig 1911 Stainless Steel Carry, no rail. It fits into the same Galco Kingtuk holster as my STI 1911, no problems.
Go to Galco's website, choose their on line catalog option, call up Colt & 5" rail gun. If my Sig 1911 fits the non-rail, your railed option should fit their rail option holster. The service and ship from Galco is excellent & if by some chance it doesn't fit, return is not an issue.
http://www.galcousa.com