The Pietta 6-1/2 inch "Navy" Remington is not historically correct, but the Uberti 7-3/8 is. Both, however, are using an Army frame on their Navy, which is not correct. The Remington Navy frame and cylinder was slightly smaller and lighter than the Army. Generally, the required format was, a Navy is a 36 caliber with a 7-1/2 inch barrel, and an Army has an 8 inch barrel and is 44 caliber.
The Colts and Remingtons by Uberti are more true to original detail, dimensions and contours, and the parts from Ubertis are more likely to be interchangable, or fittable to an original. The brass frames were manufactured by Confederate Arsenals and smaller Colt knockoff manufacturers, not by Colt or Remington, in Army and Navy calibers. It was Uberti who made all of the parts for the 2nd gen Colts and many of the parts for the 3rd gen.