The waistcoat buttons are definitely a 1970's style. There are two different buttons, but they're both from the same manufacturer because the actual dome part is the same. One of them has an engraved design with gold in it and the other has an inlaid gold design that's actually got shape to it, it's not just engraved. They appear to be 5/8". I think they're just plastic, not horn or anything, because I've never seen a blend of colors like that before in horn or MOP or anything natural. Plus, nothing in the '70s was made from natural materials.