The 7th cavalry was no different in complement of companies than Civil War cavalry: Custer divided his command into 3 battalions: he ordered Benteen with I believe 2 companies to scout to the West to insure no withdrawal of Indians had occured and thereafter, ordered Reno into the river valley with 3 companies to attack the village at 1 end while Custer moved along the ridgeline above the village to its other end with his 5 companies. One company was with the pack train which was moving up under 1 company as guard. I recall 1 company was left at the main river (Gibbon's main camp).

So the 5 companies with Custer were the men who were annihilated. You are right though that all of the companies were seriously understrength (for a lot of reasons) but there would have been theoretically a guidon for all 11 companies involved as well as Custer's personal red and blue swallowtail flag with white crossed sabers; as previously stated, the regimental was packed and with the ammunition pack train and was not in the actual battle.

I don't know if you have read "With a Sorrow in My Heart" but it is a great book about the Indian wars in the Ohio River Valley, etc. and details the life of Tecumseh and his attempt to form an Indian alliance to take back the country. The book "Warpaths" by Ian K. Steele is a great book on the eastern wars with native peoples up to 1765.

Philip Duer