identifing manufacture date of excavated 1863 new model

[venicemeghunter]

I'm new to the forum and I would appreciate anyones help identifing the manufacure date of my excavated .44 cal Army 1863 New Model revolver. It was excavated on the battlefield of the 1864 battle of Olustee here in Florida on private property with perrmission. I cleaned it up and found the serial number and what looks to a inspectors mark.
The serial # is 41785 and the inspectors mark is T T or LL. They r both on the left bottom frame under where the grip would be. The # is also on the underside of the barrel. The gun was field stripped. Only the frame trigger hammer and the cylinder remain. Thank you for any replies:)

Matt from Florida