I have made over a hundred of the twist rings, and hundreds of twist bracelets too. No real way to date it. Twist rings and bracelets are also common projects in jewelry making classes. Breezie, they still make bracelets and rings exactly like yours today. Unless there is an identifiable maker's mark there is no way to positively ID when they were made. Just because a similar common item is shown in an old catalog doesn't mean that all that will be seen are from the age of the catalog. Metalsmiths have been making these type of pieces for hundreds of years (they are simple to make), and they are made all over the world to this day.