Thanks Rossco, appreciate your comments mate.
Just have to work out the locker type_ARB air locker does appeal. Did see the US made OX locker (mechanical engagement, do like their use of a cable and in-cab lever for engagement (thinking though not available for Nissan Patrol). Have sent them an email will see what they say.
Edit: Have just received email back from OX Locker (OX_USA) and advise that:Pitty that_will move on deciding."We do not make one for the Nissan’s at all".