Excluding pioneers, there's around 15 (counting Fitz as British) Most of the possible candidates off the top of my head are borderline: Conteh Winstone Honeyghan Benn Eubank McAvoy Hamed Kane Monaghan You can make an argument for all of them, but on the flipside none of them have an overwhelming case for getting inducted.
As someone pointed out. Its merely an ego boost for attention seeking Americans. If they'll take a fvcking ACTOR they'll take anyone worthless.
Despite not fighting in ten years, I don't think he ever officially retired, or if he has it hasn't been five years since he's done so yet. Whenever he's asked, he says he's keeping his options open.