Squidge, you said there're no tuts for decrypting and seperating master and user keys available.
At Anticrack.de I found a tut which discusses the complete internals of CrypKey including how CrypKey stores license info on the HD, how CrypKey encrypts/decrypts Site Codes/Site Keys/Master Keys/User Keys, the structures of (decrypted) Site Codes/Site Keys/Master Keys/User Keys, how it generates Site Keys from Site Codes and much much more.
It's quite interesting to see that CrypKey uses Slack Space on FAT partitions in order to store the license info securely.
Also it is interesting to read how the guys at Kenonic implemented RSA into CrypKey. Very "secure"
The complete tut/essay about this "battle-proven software protection system" is very interesting and I suggest to read it