This is an Econolite Signal,commonly known as the buttonback to signal collectors,this one is aluminimum so it is pre 1990,aluminimum signal bodies ended for this model before 1990 and poly is continued to this day.
Yeah they aren't that common here too, I would say the most common type of signal here is the Fortran poly 12-8-8 with LED. BTW those MK IV peds you see are still incandescent.
@Niall you and the '97 M-400