I couldn't find Dean in any of the other units assigned to Parson's Brigade.

I therefore believe that you will find his CSR cards in Microform M331 - Compiled Service Records of Confederate General and Staff Officers, and Non-Regimental Enlisted Men, Roll 74 "De-Den."

Seeing that he was an AAC, I'll bet you'll find some very interesting vouchers and requisitions therein.

Also, here's a book you might want to obtain: "In the Saddle with the Texans, Day-By-Day with Parson's Cavalry Brigade 1862-1865" edited by Anne J. Bailey. This covers the brigade's Daily Order Book.

George Martin