Having a quick look at the EPC I see only 1 partnumber per year for the frame assy for a LHD FJ40 si I would say yes.
Similarly, FJ40 sold when the 5-speed was available have the space to accommodate one (even if sold with a 4-speed) while the FJ40 sold before the availability of the 5-speed...
Pictures I have from my skid plate on a 10/73 built with original 4-speed.
So for me it seems closer to your right one. At least the rear part is identical, the front part goes a little further on the side.
Looking at your 2 left ones they go further to the back and the only thing I see...