Grant,
It seems very likely that Una/Oona is D.N. but I'd like to have more corroborating evidence. I've never seen D.N. or Chilly or other McIntoshes referred to as Una/Oona in any biographies of them. I'm not sure that "Una" is in fact D.N. McIntosh but apparently Maxey thought so. But Maxey said 2nd Regt and he should have known better though he had only been assigned to IT for a couple of months -- of course, there can be transcription errors in the ORs.

D.N. was the more prominent leader than Chilly (who was older) and it seems most likely that Phillips would have written to Col D.N. McIntosh regarding getting the Confederate Creeks to 'turn over'. It was D.N. that Phillips was trying to contact in Dec. 1862 when he made a couple of 'expeditions' from Ft Gibson to the Creek Agency (at Fern Mountain northwest of present Muskogee) and burned the abandonned Ft Davis on his way back.

Another source you may be familiar with is the interview of Mary Perryman in the Slave Narratives. She said her uncle William belonged to "Oona McIntosh" that lived between the Verdigris and Grand east of Choska. There are a lot of McIntoshes and they were generally wealthy, had control over a lot of land, many slaves, and anyone of them could have had a farm or house or blacksmith shop or tannery etc etc about anywhere in the area.

It is possible there were close family members in the Union Army. I'm sure you know the Perryman family was split that way. I'm assuming from your name that you're connected to this Muscogee Perryman family that lived around the Porter area.

Ken