Hi,
The schematic for the "MkII" is still on my webspace, here:
http://www.technogoths.demon.co.uk/405/RGB-conv-II.png
The DVD playback issue ought to be nothing more than running the installation script when logged on as root. Typing
/usr/share/doc/libdvdread3/examples/install-css.sh then hitting 'Return' is all it should take. If it's not working, there may be some clue in any messages produced when the script is run.
Regards, Kat