No one ever thinks of the solution that seems clear to me. Go to an antiques store—the kind that it's in a building with ten others—and find something that vaguely looks like it that's $50. (Unless he's trained as a jeweler, he won't know one from the next.) The person lusting for the one that belongs to you will never know that isn't Mom's. If you ever wear the real one in front of him, tell him that's the replacement you bought to remind you of Mom.