There are a few different iterations of SII/IIa door hinges. there are ones with a mirror mount as said and then there are different castings over the years. If you do get a set, make sure they are a matched set as I have had ones from different years that just don't match at all.
The main difference is that defender/SIII stlye hignes are "self closing" i.e the door tilts up as it opens, causing it to want to close automatically, and the SII/IIa style hignes allow the door to stay in plane with the rest of the truck and not close by itself.
this also prevents the door pillar from getting dented by the door when it swings too far. the II/Iia hinge allows the door to swing a full 180 degrees, where it subsequently hits the fender and puts a dent there instead...
if the II/IIa types are not aligned just right they work loose over time. they squeak and allow the doors to move up and down. the rebuild kit is like $5 so you can fix them easily. and you will...
NAS SIII's came with a pretty good mirror mount that goes under the upper door hinge bolts. I have a set on my SII. Might be adaptable to a defender style mirror, but why bother. the SIII style mirror works ok.
Originally Posted by JimC
The rear door hinges seem to have gone through a few versions, maybe its just the addition of a center hinge, I don't really know what's what other than I know there is a newer hinge used on the Td5s etc.