Certain Suzuki SJ's shipped to Germany were equipped with a cable-operated rear differential locker. German law requires that the parking brake works on two wheels. The Suzuki's with a transfer case-mounted drum parking brake only effectively lock one rear wheel with an open differential. Therefore, until Suzuki designed a solution, the SJ couldn't be sold there. For whatever reason, Suzuki decided the better solution was to design a differential lock rather than use rear drum brakes that had a parking brake function built in.
The lever to operate the cable locker was located on the transmission hump ahead of the parking brake lever. In our Samurai's we can see where the lever was designed to be located. Also, in the dash was an indicator light that said something along the lines of "Diff Lock" that lit when the locker was activated.
Unfortunately, it was not intended for off-road use and is reportedly not strong enough for such use.
I may not be 100% correct on all of this. I heard it from Henry Von Gorkom, a Dutch Suzuki guru who may or may not read this BBS. He is on the Topica list if you want to get in touch with him.
-- Geoff Beasley