Another interesting note:A letter copied to me by Alan Johnston, written by his grandmother about their McGuffin family history, states that Thomas McGuffin (married to Catherine Coburn) was very proud of his Hugenot connection.The hugenot name given in the letter is "Barre".Thomas' father was also Thomas McGuffin (abt. 1783-1866).The info I don't have which you claim is, Thomas's wife is Jane Barr.
Putting all this together and recognizing the repeated use of the name Letitia throughout McGuffin family history, I would tend to believe that Henry P Barr & Letitia Turnly are indeed your ancestors as well.
Note: A Hugenot is a French Protestant, many of which fled from France after the "Revocation of the Edict of Nantes" in 1685 facing persecution from the catholics.
Good luck verifying this.
(This also goes out to Bill McGuffin, Alan Johnston and Shiela Church).