Is that the diff-lock switch to the left of the steering column? If so, funny that it would still be on the left. I woulda thought it woulda been easier to have everything just reversed from RHD to LHD models... Maybe it has to do with the fact that the acceleration pedals (and clutch pedal in manual versions) are in the same order from left to right, just on the other side of the middle of the vehicle... ???
Actually, what I was trying to get at was(being a smart arse that I am) that I "ASS-U-ME-D" that you had "found" those pics only after I had posted the links to the pics on the 80scool board in answer to your question. But hey, we all know what happens when you assume, right? So my sincere apologies if you found them on your own. :-[
Anyway, I'm over it since you sound like a nice guy
Now onto your question.
From what I've seen, which is not extensive, is that the F/R diff. locks here are just as common/uncommon here as they are elsewhere in the world. My buddy's doesn't have it/them and many of the ones I have seen online don't have them, either. So you and those of you Thailand should feel lucky. I know nothing about Thailand, other than I've had some Thai food and it was yummy, but your terrain necessitates having the lockers. Who knows?