Jeff interviewed the CCX guy Peter Bayer. I talk with him regularly re Smiths instruments and senders. He is Nisonger Instruments a sponsor here on Club Cobra.
You will enjoy the reading and history of your car here
Contemporary Classic Motorcar History
Thor has translated the number for you correctly. The X is like eXport and is a play on the originals that had CSX numbers.
I have some of the original CCX literature, brochures, options, the build manual etc all in electronic formats. If you would like it send me an e-mail address and have your mailbox cleared out ready. If you have any questions about your car this CCX forum on here is a great resource you've found.