pair large bakelite industrial sockets, steampunk vintage

Lot of two large old early industrial vintage bakelite sockets for audio jack style plugs. They are both marked on the socket face with "BLK" and "RED". These measure about 3 5/8" long. They are 1 5/8" long over the bakelite and 1 3/8" across the round bakelite boss. They have heavy brass inserts. The switches are stamped "303A".

They are splattered with what we think is orange shellac.