] It appears JA had a definte model for General Tilney in General Edward Mathew. While he was living in Overton, her brother James, got to know this gentleman. She took his hot temper and autocratic nature, but added to it a rather two-faced character and potentially sinister undertones.

It would seem so. It is funny how, when reading Austen's novels, I am always thinking that she must have known people similar to such and such character. Thanks for the information!