I think those purfling inlay strips are also commonly found on guitar soundholes and around the edges of the sound board (just inside the binding). Often used to beautiful effect in acoustic guitars, violins, etc...
The only other cue I've seen that used this element was a wide herringbone design from Larry Vigus. I don't know if he individually inlaid each piece, or if the material came in strips (as I'm guessing it did on this cue). Very rare design in cues either way! Great find.