I now believe this flag did indeed belong to the 69th New York at Fredericksburg. The 69th New York had the honor of the brigade and thus was posted on the far right.

Here is what the flag look like: http://www.dmna.state.ny.us/historic/btlflags/other/1-2-1Design.htm

This was the flag that BG.Kershaw wrote in his OR report at Fredericksburg.

Now the 1st Division was Hancock's. The second brigade was the Irish Brigade and the 1st Regiment...69th New York.

Have a good weekend, I am heading off to the LOC in a couple of hours.

Shawn Prouty