Similar thing guys :),
Stumbled on similar thing after returning home from Indonesia and employed with ADT ( 1973 ).
Was installing a 5125 mw in an old grade 2 listed building that used to be a corn exchange and had to rip out old system,old wooden box thing that probably jack built, not the nicest bit of carpentry I've seen,but it housed a board with four banks of relays and on a smaller portion of the board it had throw switches and clear bulbs.
The transformer was in separate bespoke box ( massive ),some components were manufactured by western co but I couldn't find an actual make/ model of the beast.
It was a contact only system but I did find and kept an old oak cased mercury based sensor with built in spirit level,again no manufacturers details.
I've seen some really old gear back in Indonesia that had been imported from Denmark but nothing like the corn exchange system :D
e manno, April 2013