I don't have an answer for you but I might have a lead.
I noticed that you have the Delcours in your family tree. The Origin of the Delcours is Belgian in the Verviers-Spa area. Near Spa there is the village of Creppe. This is where the Hurlet family originated. Now here is the interesting part: The Hurlets have from time to time when abroad used the "EY" spelling of the name.
As I said this is just an idea and may lead nowhere.
Let me know how I can help. We have been able to trace the Hurlets back to 1300.