The letter that I requested from Colt about the SAA that The Autry Museum holds as Tom Threepersons, arrived today; and holds no surprises. Shipped in 1905 to a distributor in Chicago with 4-3/4" barrel in 44/40 and blue finish. The pistol is nickel now but it was quite common for the SAAs to be nickelled by the dealer, before or after sale; and for the grips to be changed, too.
Tom's revolver has a solid form of the adjustable military iron sight found on the Colt flattop, and the only pic we have of the pistol suggests that the pistol was nickelled after the sight was installed. Theories that the pistol was equipped with a longer barrel that was cut down, because the sight is mounted flush with the muzzle, are incorrect.
Tom was a bit fussy about the sights on his SAAs, because his other SAA also has modified sights: the rear sight has been 'clearanced' by actually cutting deeply into the topstrap just in front of the rear sight, tapering back up to full thickness near the cylinder face; and the original front sight has been made smaller/lower. He took a file to other parts of the pistol, too; and a penknife to the mouth of his holster to lower it.
P.S. I swiped my 'Variegated' title for my Hoyt thread, from the article about this man with whom at least one period newspaper article compared Tom Threepersons ("Exploits of Tom Threepersons Rival Experiences of Diamond Dick Himself", OREN ARNOLD) in which Tom's mythical companion named White first appears (and who himself may have been given his name by Tom's real life ATF partner):
"The Variegated Life of Norfolk's Diamond Dick", L.B. Finch. Nebraska History 84 (2003). Dr. Richard Tanner b. 27 Nov 1869 d. 02 Jul 1943.
Can be found online via Google.