> Er, have you tried using /usr/share/X11/xkb instead of /etc/X11/xkb?
~$ setxkbmap -model pc104 -layout pc/czsk -print | xkbcomp -w0 -I/usr/share/X11/xkb - :0
Error: Can't find file "pc/czsk" for symbols include
Exiting
Abandoning symbols file "(null)"
Error: success in unknown
Couldn't write keyboard description to :0