Reports and letters by members of Wheat's Battalion do exist. Wheat's report (as Homer Martin wrote earlier) exists in a number of versions, letters from or contemporary accounts by some 7 officers and enlisted men also survive. None make any mention of the Battalion taking colours during the battle. I think that it will take a process of matching and elimination to answer the question of which Federal unit the colours "Shanks" Evans mentions in his report belonged to. Finding out which Federal units lost their colours (would they publicise this?) and, like Shawn has been doing, working out which Confederate unit took credit for capturing them.

Regarding the stories about Wheat's Battalion engaging Fire Zouaves and "Sherman's Battery."

Two letters from Wheat's Battalion tell of a knife charge made on the "New York Fire Zouaves" (both letters seem to be by the same author and no other letters or reports make any mention of this).

A Captain in the 8th Louisiana reported that a Federal prisoner told him that "Sherman's Battery" [many Confederate reports refer to this battery - they probably referred to Griffin's, Ricketts' or the Rhode Island Battery whose guns were all captured] was taken by members of Wheat's Battalion and a South Carolina regiment who had crawled for nearly a mile on bellies through bush before charging with the bayonet.

Given the scattered state of Wheat's Battalion after the morning phase of the battle of 1st Manassas it is likely that members of the Battalion did engage with the 11th NY and "Sherman's Battery."

Not an answer but, hopefully, saves someone from having to track down some info on Wheat's Battalion.

Ross