I'm the OP. I bought a lightly used Custom Shop 97 BD from the LGS a few weeks ago. I'm not worried about it being/not being a CZC gun; it has the CZC marked bushing, the box with the CZC label, and the shiny aluminum grips with black grip tape (replaced those with LOK carbon fiber grips). But I saw the czc in the triangle on the slide--didn't seem to be a proofmark, since not on the frame or barrel. But. . . then I got the bright idea of comparing it to my TSO (which required some digging in the safe) and whadda ya know, there it is, although on a different place on the slide. Well, duh.
So not a Custom Shop mark, but I still am curious what the mark is. Does it stand for the equivalent of CZ in Czech?