Jeebus! I've been battling the Server to let me back in and reply to my first post, apparently I don't "Have permission". Does this to me every few weeks and I can't post anything at all.
Anyway, had the answer all along, the first posting was just to refresh memories about Tell's original question.
The bracket is mounted in the left side rear toolbox, in all the 6x6 versions I've seen. It is to secure the vehicle jack.