Back from a trip with a few oddities. These spoons are very odd indeed. The back of the bowls look French the handles look American. Normally that would suggest to me a Canadian or Mississippi Valley origin. But the marks IZ or ZI look like Scandinavian or Italian, with those little circles around the inside of the cartouche.
Looking at these photos, I should have chosen another spoon, but take my word for it, it is a thick ZI Or IZ.
Maurice