Dave, I don't think it was a WiaD machine; I don't see the round cover for the fan on the back of the base.
I also notice that it has another unusual box on the back of the saddle, at the end of the cross-feed screw, where the taper attachment mounts:
That suggests an electric taper function, as rabler suggested, however I don't see any wiring coming from the box to support that idea. Another thing that argues against that is the lack of any additional controls or electrical enclosure to support an electric taper or feed mechanism.
I don't have a good photo of the cavity behind the square plate on the end of the bed, but there's a lot of space back there. Easily enough for a motor:
photo by DaveE907
The square hole and cover on the end of the bed seems like overkill just to access the ELSR wiring. It's more likely that it was put there to allow for some sort of accessory to be mounted inside the end of the bed. As far as wiring goes, cables can be routed through the bed or down into the base.
Anyway, this is an interesting machine!