I have stayed up till three in the morning trying to find another "Google Book" that sheds light on this flag. This Saturday I am heading right over to the LOC to check on this. I will make sure I record the book, page and author. I will also lists the author's sources. It's out there for I have found it once before.
I will report back what I find on Sunday. I work on a list of Union regiment's I "suspect" lost a flag in battles.
Have a good day,