Hello Colleagues!
Thank you for your quick replies.
I have the various sound listings for each board, if anyone is interested.
In summary, Board 1 has 236 sounds; and Board 2 has 186 sounds. Bob is correct about the "Celtic voices."
Board 3 has 246 sounds covering rare synthesizer sounds. And Board 4 is called a Super Sound Board of 186 new sounds and Frank Bez has already commented on some of them.
The reason I'm after the No 4 board & the foot controller is simply to complete my KN7000 line-up.
I'll keep looking on Ebay. Thank you for your comments.