"The knurling on the hammer seems different from that era, but it could still be correct."
Good eye, Shrapnel! It is a later period replacement hammer. Fortunately, I had a proper period hammer with the correct knurling pattern that I installed in the gun after the pictures were taken.
The barrels on both the Navy gun and my gun are 6 1/2" and came from the factory in that length. Moore quotes in his book communication between Colt and the Navy concerning the specifications required by the Navy of a 6 1/2" bbl and 38 Long Colt caliber.