Lt. Col. Donald Penobscott
This character's name puzzles me, which distracts me from the show whenever he's mentioned. There's a river and a town in Maine called Penobscot (only one "t"), which are both named for a local Indian tribe. So it seems odd that the character would bear that name unless they specifically intended for him to be a Native American. But if so, it was never mentioned.
My best guess is that they saw the name on a map and thought it sounded snobbish, and would therefore be appropriate for a man who would appeal to Margaret.