I always thought of bolas as necklaces for men that are worn on the outside of the shirt. I think I have one or two of them stuck away in some drawer some where that I haven't seen for years.
I think that they are still around here somewhere: one with yellow and black cord and tiger eye stones at the ends and slide and one with IH on it that Dad had when he worked for IH.
I have an ivory bolo tie clasp carved as a growling polar bear's head. My dad used it in Anchorage as a key fob in the 30s to keep the mail key. He scratched their box number on the back of it. It's special.