Hi Trevor,
Yes, you can use a second keyboard and a pedal board with the KN7000 to effectively create a 2 manual organ with pedals but to acheive this you also need a MIDI merge box to combine the 2 sets of data before they are fed to the KN. You connect the MIDI outputs from the 2nd keyboard and the pedal board to MIDI inputs 1 and 2 on the Merge box and the MIDI output of this to the MIDI input on the KN.
Make sure that the MIDI input switch on the KN is NOT set to pedal mode otherwise all inputs will be played on the bass pedal part.
You will then need to assign appropriate MIDI channels to match the external keyboard and Bass Pedals to the parts you wish them to play.
Suitable MIDI merge boxes are available in the UK from Phil Rees.
If you require more info don't hesitate to contact me either on this forum or directly.

Cheers
Len C.