I was just looking on google and saw a website about Johnson's Tennessee brigade at Drewry's Bluff. They claim to have captured the 19th Wisconsin's flag (which one, it did not say).
I doubled checked to see if the 19th Wisconsin was at the battle. They were in the 18th Corps (MG.Smith's), 1st Division, 3rd Brigade (Col Sander's). The 92nd New York, 58th Pennsylvania, 188th Pennsylvania and the 19th Wisconsin were all in the same brigade.
I am going to toss out an idea, I think the other flags captured were the 92nd New York and 96th New York. I checked the history of both, they only saw major action during the seven days battle, (4th Corps) and at Drewry's Bluff. My old post of "Returned Battle Flags by the War Department" has both of these regiments losing a flag.
Well just a thought on the 92nd and 96th New York. I have found no proof yet, but I am searching.
Have a good weekend,