Ok. With those files switched, he appears in the kitchen (old model)... but when I put the new models in again and tried to replicate his disappearance, he appeared (new model). I have installed the newest version since last night, but DLPB would have known yesterday if he had changed something there that would fix it. I can't imagine how Bugenhagen could possibly have been on screen and I didn't see him when looking for him: he's shiny and bobbing up and down, so I gotta figure he really wasn't there the first time I played through. Well, all's well now.
Also, the change back and forth was startling: amazing work.