Looking closely, the whole thing appears to have been slapped together using random pieces. The "terminals" are just riveted to the back (unusal, I think equipment of that age would have used screws and not those cheap rivets), the wire apparently connected to the far right knife (bottom) is connected using a choc block maybe good for 10 amps and sure to melt down confronted with more than say 20 amps, the wire doesn't appear to be any bigger than 1.5mm2 (18amps in free air I think) and the wires at the top terminals appear even smaller. The far right putty knife is obviously broken in half. The top terminals just seem to be jumpered and the far right terminal seems to be half gone altogether.
I say it's some crude joke and at worst used to control 12V if at all (the choc block does seem to indicate some kind of actual use though).
