From your description I would not assume the Colt is a 2nd Generation. The box description does not have enough detail to identify it. If you can post a picture of the box would settle if the box is 2nd Generation or Signature series. The Navy could also be in the wrong box.
As DoubleDeuce 1 said both the serial number will help as well as if the Navy has the little engraved "Sam'l Colt" signature near the top of the back strap which indicates a Signature Series. Have seen the signature taken off or filled in so be aware of that as well.
Regarding 2nd Generation Colt 1851 Navy boxes the earliest ones are small, hinged lid, black covered outside with Colt logo in golden color on the lid's top center. The inside is mostly dark green with some outside black covering folded and secured inside. These boxes were used for a few thousand Navies.
Next was a small hinged lid brown and very light brown outside box with the cylinder's naval battle scene copied on most of the box lid. The third box was a wood grain box, with end flaps, having an insert of two piece rigid styrofoam. All these boxes were for the " C " series model prefix.
Then about 1978 came the " F " series model prefix with the big black, thick boxes, with the grey flexible foam insert. These big boxes were continued until production stopped in approximately 1982.
Did the literature you saw state anything about Colt Black Powder Arms Company in New York? If yes, that is Signature Series literature.
Again, the serial number would be very helpful as well as close up pictures including the serial number.
