It took me a few seconds to figure out the shape of that green wall phone -- It's certainly distinctive!
I'm wondering if that black 500 set pictured was made for Canada. The normal American version would have "Operator" marked on the zero digit, but I've seen several come from the Canadian market which omit that. Can any of our members from Great White North confirm whether the absence of the "operator" marking on zero was the norm for Canada?
Some of the other non-Bell companies made 500-style phones, but with some minor variations. If you look at some Automatic Electric/Stromberg Carlson models, for example, you see that the dial spacing was slightly different so that the zero ended up right at the bottom.
Here's a British GPO 746 phone in mustard yellow:
This type was introduced around 1967, although the 706 model it replaced was very similar.
The internal layout is different than the 500 sets:
Compared to this GPO model, the 500 has the bells at the rear and the network circuitry incorporated into a sealed unit.
The GPO 700-series handsets are also quite a bit bulkier than the American WE500 equivalents.
{ Edit on 4/22/05 due to images no longer being where they were 2 years ago! }
[This message has been edited by pauluk (edited 04-22-2005).]