Hard to tell just by looking, but it looks like the latch on the C-pillar is normal. So it's the latch on the seatback that is going to be doing this 2-position thing. So it would involve buying and shipping some rear seats from a market where this option was offered. I'm pretty sure that was never offered here in the US market.
And often, the upholstery patterns and colors were not the same in JDM Hilux Surfs, sometimes a little wilder/jazzier than what we got. So you might want matching front seats. And sometimes the seat upholstery matches the door panels, so you might want those.
Yeah, at that point, just go for broke and bring over the whole JDM Hilux Surf, and get one loaded up with some other unobtanium parts while you're at it, like a 5-spd 1KZ-TE drivetrain, rear tire carrier, spoiler with the weird drop down mirror, front fender mirrors, etc. 1996 and 1997 cars can be imported with 'relative' ease at this point, 1998 will be in a couple more months.
There's a company here in MO that specializes in bringing over JDM Toyota trucks, but it looks like they generally don't bother with Hilux Surfs, since I guess it's hard to justify the resulting prices they need to make it worth their while for a funky 3rd gen.
Land Cruisers Direct - Vehicle Inventory
