The serial number of the clipboard is in Settings->System->About, but not for the keyboard section. Physically, the serial numbers are on the connect edge of the clipboard and on the bottom of the keyboard near the hinge.
As far as a CD-key, I think MS is moving away from that for pre-installs and upgrades. They use a HW fingerprint instead. You still get a CD-key if you purchase a retail version of Win 10 I believe, but other installations are recorded in your MS account instead.
Finally, there is a recovery partition on the disk that probably has the data for reinstalling the OS, though it is only 800MB so unless they've done a lot of compression it may not be complete. You could go into Disk Management and assign it a drive letter and poke around at it and copy it to an external drive, but I'm not sure if it will fully replace an install CD/DVD. Perhaps it installs a mini-OS that then launches and downloads the full Win 10 OS?