I spotted this photo with what appears to be a few older UK low pressure sodium lights that were used to spot replace the original incandescent gumballs. The photo according to the uploader was taken at the start of the QEW in Toronto just west of the Humber River in 1957. I'm not sure on the model though.

Interesting!, given the year they could very possibly be GECs Z9451? 

They sure look like the GEC Z9451. I've seen a GEC Z8128B here before so I'm not surprised at seeing other GEC luminaries.

It would be interesting to see if they had 140w SO/H or 140w SOI/H lamps in them.

Now that’s a difficult one  , as BOTH types were available in 57  , possibly the SOI as they were new installations?

Interesting, never saw this kind of spot replacement along the QEW

Yeah, I wonder how long they were used for too...could be for a rather short period if they were replaced when the Gardiner started construction a few years later in the 1960s.