Colt will tell you the manufacturing date over the phone. If you want written proof, it's $25.00, and a 4 month wait. If you want a complete description as to how it was configured, that's $100.00, and again, a 4 month wait.
Go to Colt's website, and then to the historian section.
I would highly recommend at least the $25.00 DOM proof.
You just never know when some idiot company is going to have a fire in their office and loose their records.
I'm going to start requesting manufacturer's documentation, even on my postbans. You never know when a company might loose their records, or go out of business, and what the future political climate might be.
It's too bad manufacturers can't send along a little postcard with DOM and the configuration it was in when it left the factory.