Not sure how complex that would be here, just moved here a couple years ago with my Canadian truck after driving it all the way to Panama
Lack of donor would certainly be the first issue in mind. I know less than a handful of scrapyards on eBay with 3rd gen Hilux Surf (all RHD diesel) and never seen any 4Runner anywhere. 2nd gen is a bit easier as it was sold here (probably different specs/trims still).
Problem for the 3.4L in Europe is that, in the eventuality it existed, it just wouldn't sell because of the gas price. I remember when meeting other overlanders during our trip, most Americans would always tell me they liked the 4th gen better because of the V8, while ALL Europeans would drive 4 cylinders of whatever vehicle they had (often diesel). And A/T practically didn't "exist" until 2000 in Europe.