I'm not sure I like the look of those...it's like a normal 4Runner got into an accident and became smushed. Probably because of the gigantic rear side glass.
Anyway, does a D4D engine communicate with a conventional OBDII scanner? If so, you are probably looking at one of the sweetest Taco/4Runner engine swap candidates out there. Aside from cool factor of just having it...I would probably pass. Even if you do the swap, parts will not be quick to come by simply because the engine doesn't exist state side. Another major thing going against you is that even though the truck physically sits right in front of you doesn't mean it came in legally or has the necessary paperwork. It may have been an "embassy" import but it simply doesn't comply with EPA and DOT regs. Unless you plan on spending the kind of coin it takes to swap over to DOT compliant lights, lenses, glass, cluster, etc. and prove that it meets emissions (including fuel filler, EVAP, tail, etc.), you would still have to crash test it to prove it is safe. I'm pretty sure only then will the DOT sign off on it. The only reason you could do this is because it is similiar to a chassis we already have, just shorter.
Even if you bypass all that BS and just manage to get it titled or registered in some shady state like Florida, the man eventually will find you. If he doesn't, you will be sweating big time if you get pulled over by a LEO that knows his stuff. The feds are cracking down hard core on grey market imports. Mostly stuff like Skylines and Defenders but it wasn't a cake walk like ten years ago. I think the more you research, the more you will find that it is damn near impossible to pull off "legally".
Now if you wanted to use this on a farm, incorporate it as an engine swap, build some kind of custom vehicle that you could get a custom tag/VIN applied to it...probably much better off than a daily driver.
Either way, cool truck and I'd drool over it if I saw one in person too!