I have a 97b in black polycoat. Had it quite awhile actually, but it was not until today the I noticed a before unseen marking on the frame. On the right side of the frame, starting below the foward edge of the ejection port is "CZ-USA KANSAS CITY KS."
If the light is not just right, ie direct sunlight and the gun held just right, it's neigh on invisible! Shows in the strong artifical light of my Xenon flashligh as almost a bronze coloer. But just looking at the gun, it's almost impossible to notice, at least on mine anyway.