Nuthin' fancy here: it's a bog standard bracket for a Rickenbacker-style trapeze tailpiece or Kauffman vibrola.  Identical to the contemporary Rickenbacker trapeze bracket, it's compatible with all the trapeze tailpieces that we sell (6-string, 12-string, long, bass, etc.), as well as the Kaufmann vibrola.

And yes, the mounting screws are included.

Trapeze/Kaufmann tailpiece bracket