NPS CWS&SS shows:

Andrew J. Morrow
Regiment Name 17th Texas Cavalry
Side Confederate
Company H
Soldier's Rank_In Private
Soldier's Rank_Out Private
Film Number M227 roll 26

Henry Seelbach
Regiment Name 17th Texas Cavalry
Side Confederate
Company H
Soldier's Rank_In Private
Soldier's Rank_Out Private
Film Number M227 roll 32

William Seelbach
Regiment Name 17th Texas Cavalry
Side Confederate
Company H
Soldier's Rank_In Private
Soldier's Rank_Out Private
Film Number M227 roll 32

17th Regiment, Texas Cavalry (Moore's)

"Units of the Confederate States Army" by Joseph H. Crute, Jr. contains no history for this unit.

Roberts, Gov. Orin M.
- Confederate Military History - Texas Volume - 267 pgs.

Rigdon, John C.
The Civil War in Texas

Rigdon, John C.
Texas Civil War Soldiers Index

The Southern Historical Society Papers

Information seems scarce.
JR