Rich - In numismatics it's known as a reeded edge. The Green Mill Inn, Greyhound Club and a few others I remember had at least two of the three known edges. I recently had some "unfinished" Crest & Seals where the lip around the edge of the chip was still sharp (approx. 1mm). I could understand the generics having two or more edges, but I don't know why some of the club chips are also found this way. I also had some very interesting "combo" Crest & Seal / Inlaid chips. One side was a full-blown C&S and the other an Inlaid. They must have cost a pretty penny back in 1930. The president of the Asociacion Numismatica de Panama took them off my hands. Had some nice Mirimar and Club Union chips in that find. Also located some oversized inlaids with reeded edges. I don't know anything about the Stagecoach chips, but I remember Mel once mentioning they were used in some CA club...or.

Below is one of the rarest ivories known. In fact, there are only two different design oversized "50" ivory poker chips known. One in The Dale Seymour Collection (IP-TH) and this Papa.