The Pietta that is offered by Cabela's is indeed an 1861 with a non standard barrel as was pointed out by coyotejoe. Uberti and others have made closer copies of the Pocket Navy and the Pocket Police Colts. Not sure if anyone is currently making a correct copy but sometimes you can find a used one. Not too often as those that have them, like them!
Here's a photo to consider.
My Pocket Police by Uberti
And my Pocket Navies, also by Uberti
These were originally built on the 31 caliber frame and used the rebated cylinder, ala the 1860, to gain the diameter needed to increase the caliber. Newer steel technology used by Colts allowed this to happen. The revolvers made using the 31 frame were more numerous than any other Colts model produced. Once you handle one, you will see why. Although I do like my 1861s, when I carry a 36 it is usually my Pocket Police.