Yeah, I thought about spelling it that way, but feel it's "too Yankee". Too close to the Nordic name Ole, like as in Ole Oleson. Southern? Too close to the deeper South, olé.
Either way works. I'm an old comic book fan, though, and whenever I read Sgt Fury and His Howling Commandos, Reb always was written to say it as ol'. The ol' hound dog. The ol' homestead.
Come to think of it, though, considering its considered a proper name, Perhaps Ole Miss would be correct.
Damn, now I have to write a professor at Mississippi and ask him/her which is the proper usage.