This one decided to come to live with me. It's the smallest I have. The shell hilt is .307" thick (7.8mm). the diameter of the ferrule just behind the guard is .278" (7.04mm). It has a nicely made monosteel blade that is .076" thick (1.93mm).
I'm not sure if it's a childs piece or a miniature. The materials and workmanship are good. Thanks to Lotfy for letting it come home with me.
Steve