You will find some interesting information on the unit and Brown's company as follows:
Buff Facings and Gilt Buttons by J. Boone Bartholomees pertains to the staff organization of the Army of Northern Virginia
Couriers, Orderlies, and Escorts, pages 205-208
http://books.google.com/books?id=fJPOL-2VfoMC&pg=PA207&lpg=PA207&dq=39th+Virginia+Cavalry+Battalion&source=bl&ots=pRtfz0cgGQ&sig=KvjdZHBl0ezcsjJyk-WQQc48Pzo&hl=en&ei=J1NFSpCYG4WIsgOl-dTRDQ&sa=X&oi=book_result&ct=result&resnum=4