Two Different Vintage Seashell Necklaces Coastal Beach 18 Inch Long

These vintage seashell necklaces were purchased in a Florida souvenir shop in the late '60s. I don't know where they were made, but they are great for the Island Beach look. Have only been worn a couple of times each. Each one is about 17-1/2" long. It looks like one might be missing a Cowrie shell in one spot, but I've seen my mother-in-law wear it and I never noticed anything missing (see pink arrow). Could be used for wearable jewelry or crafting upcycle.