80 series Landcruiser diffs

Ah, why not? I was thinking of getting a rear diff lock, maybe an air locker, but was thinkig that if I could get a complete rear diff assembly (with diff lock) from the wreckers, put a switch on the dash to operate the eletric diff lock, might be a cheaper properistion than a new air locker.
Must be missing something in my thinking? Elictric diff lock, must be 12v, power on to engage, power off to disengage?

Toyota had locking diffs for both front and back on 80 series, why don't you get both? Might be worth running power through relays first. I'm nor going to go out and check our 80 series, but according to THE book, there may be part of loom built in.