Trying to figure out what Jensen done is part of the fun of collecting them. Just when you think you got it figured out you find something different. I have only seen 2 with the stuffing box , cap, and 4 screws in the side of steam chest. I'm sure there is probably more out there. Kinda strange that both are 20s with generators hooked to them. Wonder if he was trying to seal them up better to get more power from them to pull generator better.