Interesting...
..that everyone seems to have questions about authanticity of the weapon. My first thought when I saw photo was why was a Colonel carrying a Bowie knife and not a sword.
Frederick Bass was indeed the last commanding officer of the 1st Texas, listed as a full colonel when the unit surrendered at Appomattox. At one point earlier he had even commanded the Texas Brigade for a brief time (to which the 1st Texas was assigned) so I find it even stranger that he carried a knife rather than a sword you would expect of a senior officer. Has this rig been assembiled from individual pieces or did it actually belong to Col. Bass?
On the revolver cylinder I think I can make out what appears to me as very crisp numbers, upside down, but my eyes are not good enough to actually read them. The spare cylinder in the cartridge box just adds to my feeliing that this is all a staged assembly.
All the earlier questions and points would all indicate this is probably not a "legit" original. That said, it also true that you can not really make a positive judgement without physically seeing and touching both the pistol and the accutrements.