That might be true too. You're right that the socket would be inconvenient as a connector. But it kind of seems like a large device to use as a as a current sensitive resistor and/or fusable link. I would have though a smaller device could have been used instead.Maybe it is a fuse socket? Remember the large current fuses that were used in house wiring panels before circuit breakers became common? Do you think maybe one of those kind of fuses is used in the socket?
It would be interesting to know.