Sorry for the double posting-my computer is on a rampage!
Here are some unit references at various times in 1865, and a bibliography for Rip Ford.
3/31/65 Organization of troops in the Western Sub-District of Tex, commanded by Gen Slaughter
Western Div Col Santos Benavidez
Five Co’s of Cav, Benavides' Regt
Southern Div Col Ford
Benavides' Regt five Co’s Cav
Cater's Bn, three Co’s Cav.
Giddings' Bn, six Co’s Cav
4/28/65 Houston Tri Weekly of 5/12 issue-discussing Ford’s command as being in the main as good as soldiers anywhere:
& a large portion of the 4th Az. known as Showalter’s Regt
John S. Ford, Memoirs (MS, John Salmon Ford Papers, Dolph Briscoe Center for American History, University of Texas at Austin).
John S. Ford, Rip Ford's Texas, ed. Stephen B. Oates (Austin: University of Texas Press, 1963).
William J. Hughes, Rebellious Ranger: Rip Ford and the Old Southwest (Norman: University of Oklahoma Press, 1964).