Thanks for the suggestions, Timpo. I didn't end up using them, but they led me to a solution that should work.
None of the replacement clamps will fit the CCX because it's using a 38mm tube with a 34.5mm shim inside. The security clamps don't seem to be available larger than 34.5mm, so they won't fit the CCX's outer tube. The Sphyke combination lock nut won't work either because the existing bolt has a hex head on the other side.
Solution: Hexlox makes a replacement bolt that should fit the existing clamp. The parts you need are the M6 Universal Security Set For Seat Post and a Hexlox key. Total cost is $40 US dollars.
Hexlox is the only real saddle lock that can easy protect your saddle & seat post from theft. Just insert Hexlox into existing Hex Bolts to secure saddle & more.
hexlox.com