Four cylinder Navara/pathfinder/Terrano models usually only have a smaller C200 diff with 29 splines (these will however fit into the front diff of older MK patrols).
Yeah I think thats just the early nat-atmo diesels and gassers.. all the turbo diesels I've found have the dropout type H233 rear diff too. So long as it looks like this and its from a WD21 it should fit:

However I wouldn't recommend a tightened LSD in the front I pulled mine out and replaced with an autolocker as it steered like a pig with the tight LSD in the front.
Yes agree its a compromise, personally I find it manageable unless at realllly low tyre pressure, then maneuverability is compromised a bit. With the tyre/rim combo/vehicle weight/driving style I find it to be a decent trade off. If it was a high speed desert racer, military unit or trials vehicle then it wouldn't be good. But neither would an autolocker in the front, IMO.
The benefits I see of the C200 front LSD swap is that, as a 4-pin design, it is a remarkably strong carrier and solves the solid axle C200's problem of wallowing out the center pin and blowing up. I also wonder how much wear of the clutches is accelerated in a tightened rear LSD application. But It seems they keep going and going. In the front, I dont thnk it will ever wear out.
Plus I dont know if it is just a psychological factor, but I feel that the front LSD is kinder on the running gear. I realise that the LSD will only ever transfer 40% of available power to the other wheel... in any event I have given it a heavy rodgering on several occasions, sections where I knew that I would either make the obstacle or break a CV/hub. So far so good.
Charo your SWB MK from the Patrol forums is very cool.