Gedday,
one thing I've found from listening around and reading is that the SIII was less customised to mil spec than previous Series Landies so it's possible it had the normal LR jack and wheel brace. Rovers North (and possibly other parts suppliers) sell OE wheel braces and jacks. For mine I have a 3t bottle jack (to cater for when it's loaded up for a trip) and the OE wheel brace.
hope this helps
Daryl