I think we need a bit more info than an unfired Colt 1851 Navy before making observations.
I agree with Dave about the CC BS TG. That is something unheard of to me. If I had the money I would have bought it just for the anomaly if I had the pics of it, as in you might have a rare replica. Stranger things have happened.
Pics, please, with all the good stuff like manufacturer, date code, proofs, et al. Can't believe it is a Colt 2nd/3rd/whatever Gen pistol.
Jim