These are still made by a company called Boltswitch. (
www.boltswitch.com)
Apparently, they are designed to take the place of a breaker in panelboards by other manufacturers.
This particular installation looks really scary due to the corrosion, if for no other reason (that is assuming the deadfront is not lost, but merely leaned against the wall out of the picture). The fact that one cannot distinguish between rotten wood and rusty metal (which is it?) is symptomatic of this fact.
