What I did back on my KN5000 was similar to the above reply. I made a unit out of wood, and drilled holes to install Allen Organ "Thumb Pistons". These are the same kind used on pipe organs. Worked great. Back on my KN2000 I had 8 of these, which I hand-wired to various controls on the keyboard (literally by opening up the keyboard and running wires to panel switches)-I'm sure this voided my warranty! This was because back then, they didn't have the 4-way switch jack like they do on the KN5000 and later.