No - I don't think the technology for that was around when this was invented. Hornetdownunder may have seen one of these....
No to all. They were invented in 1936 and used regularly in Melbourne through to the early 70's. A fairly commonplace item, the colours give a strong hint...
Yup - they are Marshalite rotary traffic signals. Don't know why they stopped using them really - quite cute. Your turn...