Yes that surround and switch is unique to L Series AWD cars . I managed to get the surround and sticker but not the switch . I also have the Vortex switch but never fitted either .
I don't off road my car and have never had the need to lock the diff on the blacktop .
BTW the L AWD DR/SR boxes go straight into any manual L Series with no differences other than the stay rod and shift rod length , ah and make sure your drive shafts are using 25 spline DOJs because that's what the L AWD box has std .
Make sure there are no remnants of the speedo drive cable in the gearbox before you fit it because they are a bi*ch to pry out with the box in place .
Also , important hint , unbolt the vac unit so that you can get the gearbox up high in the trans tunnel to bolt it to the engines flywheel housing - in an L Series anyway .
Also , important , make sure you grab the AWD boxes wiring sub loom because its different to the PT 4WD one - switches in different places .
I think it plugs into the ordinary cars body loom side and should light up the 4WD and Low Range center dash lights .
I'm just using the LR wiring though its not hard to tell which range you're in if you have the non turbo L shorter LR gears like my hybrid AWD L box has .
Very handy to have a syncro high/low range and makes tight parking maneuvers a snap .
My box also has the non turbo closer ratio main gearset which is a hoot at the traffic light grand prix , never fall off the boost curve ever again though not so good on the expressways .
Some people find the wider taller turbo ratios not to be so good in a carby L Series though after a Brumby four speed the turbo 5 speed would be rather welcome as in closer than what you should have now . I wouldn't think a Brumby has 3.7 diffs so may need to grab that L's rear diff .
There's obviously differences with using any L Series five speed gearbox in an MY/MA but the changes would be the same because the L part time and full time boxes are for all intents and purposes the same .
Really the only external differences , aside from the vac actuator , is the AWD one is deeper in the extension housing at its lower rear .
No doubt people here would love the gauge cluster because the center bit lights up Diff Lock when locked . They also had a couple of extra gauges the more mundane versions didn't get .
For the drive experience you will notice that after the conversion your car will feel more sure footed everywhere and nothing like you typical FrWD POS .
You have less load on the front tyres contact patches so they don't tend to skip and screech over humps bumps etc . Also you can launch from a standing start on wet roads as hard as you like and not spin the wheels in the wet . I'm only using 185/70/13s which are no disadvantage at all in a straight line .
My RX has a bit more squirt that your average EA82T powered L and it doesn't spin wheels except over one sharp hump tight right hander intersection and I have to have the boot right in to make it do it .
Off cambered up hill tight roundabouts in the wet with the boot in , minimum understeer though I've altered geometry and have big anti roll bars under my car to take out the average Ls take the chrome off the door handles body roll .
Nothing like driving an Evo Lancer but very passable for a mid 80s car .
AWD will spoil you and make you hate not having it in other cars .
You have been warned , cheers A .