I do not think that everything in John’s Gospel can be verified historically in these ways. As with any other historical source, what needs to be assessed is its general reliability. (This is the best reason why commentators are either consistently skeptical of historicity in John or consistently inclined to accept it.) If the Gospel is judged trustworthy so far as we can test it, then we should trust it for what we cannot verify. That is ordinary historical method. Probably the many points where