Anthony,
On my long list of Union regiments taking CS flags I have both the 2nd and 3rd Michigan Cavalry as taking flags in the Island No. 10 Campaign. I checked the book on the 2nd by Thatcher but made no note of it mentioning any flags (and believe it or not some Union unit histories do NOT mention taking flags!).
Let me get caught up with being away for four days and I will see what I can find for this.
Greg Biggs