The saber looks to be the Model 1840 cavalry saber, probably a photographer's prop if he is from Texas. His uniform is similar to a picture I have of a man in the 18th Texas. The picture has been touched up or high lighted by use of gold gilt paint. I hate when this was done back in the day, as it hides items such as buttons, buckles and other pieces, that if left unpainted might tell more about the subject, such as if he has Texas buttons on the coat or other information. The buckle looks to be a brass CS oval, maybe even sheet brass. I believe this would be rare for Texas, but again it could be a photographer's prop setup.