Melba,
Thankyou, thankyou, thankyou...you are an absolute genius!!!!!!
So happy - this is exactly the sort of information I had been looking for, but couldn't find.
Just found my lovely Grandma

.
I followed your steps. Under Finding Aid 31-80. I found the street name (in Toronto) and got the 1931 district number and the subdistrict numbers that cover that street.
Then, I went to the list of districts for Ontario and found the name of the district that corresponded to the number from step 1.
From there, it was just paging through the subdistricts until I found her.

I will use this technique to find the rest of my City relatives.
Thanks again!!
RK