Great job, on this Tom! I just have to cross check what other Union regiments were in the 27th Mass's brigade and hopefully that will help out a little on the other flags captured. I see that the 27th Mass was not in the 10th Corps. The 27th Mass was in the 18th Corps and took a beating at Cold Harbour (Stannard's brigade) Martindale's Division. If 4 flags were captured and the 27th Mass still had the same brigade organization at Cold Harbour then it looked like this:

23rd, 25th, 27th Mass
9th nj, 89th ny and the 55th Pa.

I dont know what other flags were captured at the battle but this brigade was very hit hard at Cold Harbour. The 25th Mass lost the highest percent 69%. So it is possible that maybe they lost a flag at Drewry's bluff.

Well, again thank you for the information on the 27th Mass.

Shawn