Welcome to the Colt forum from Pa . The SAA ( single action army) is valuable in itself because it is a first generation Colt model 1873 with a black powder frame. They are highly collectable. Then you add on the period or original up grades such as the fancy grips and plating as well as period engraving. Top that off with the original box that it was shipped in . Wha !!!!! Hoooo!!! A Holy grail gun. If the Colt letter reads that's how it was shipped,or shipped in the white so it can be engraved. That will prove its originality. That's what makes it valuable to us. Your pap makes it valuable to you. Thank you both for your service.