Hey
Stewart,
Not sure how much help I'm gonna be, but I have one possibility for you. Of course, we have to overcome the fact that D'Leon is a legit Spanish surname in Venezuela (notably
Oscar D'Leon, the salsa music guy) and elsewhere in central/south
America. And maybe that's the true origin of your name; but you have reason, apparently, to think otherwise.
If we go with the Irish connection, we stumble on the coincidence that "leon" means "lion" in Irish Gaelic as well as in Spanish. But if it occurs as a surname in Ireland, it's pretty obscure.
I'd put my money on a common Irish surname, that upon sight anyone might translate into a form of "leon" in Spanish. That surname is Lyons.
Lyons comes not from "lion" or "leon" but from one of two ancient Irish patronymic ("son of") names, either O Liathain (County Cork) or O Liaghin (County Galway). Liaghin derives from laighean, "gray". Not a clue what Liathain means (
Phyllis?).
Anyway, if I had to pick an Irish name that was translated into D'Leon once in Venezuela, I think Lyons is the most likely.
Like I said, a possibility.
Hope that helps.
-
Daividh