Below are official records which the Ontario government published annually regarding the ownership of each plate registration. They were small passport sized books titled “List of Permits to Operate Motor Vehicles in Ontario”. As far as I know, Ontario produced this book from about 1903 to 1912. After which time registrations exploded and it was likely too tough to keep track of. As an example, the two books I gained access to (1906 and 1911) contain 39 pages and 129 pages respectively. The other issue was that late year registrations were never captured in the book due to the manual process (ie: record gathering and pure publishing time frames). In essence, they were already outdated when released.
The shear size of the scanned images is too large to publish on the web. Instead I’ve manually transcribed the books into open source spreadsheets so that the license plate collecting community may reference as need be. My intent is to share this important historical data with all. I’m hoping to expand this section as I’m able to find more annual additions. Thus far I’ve only been able to find the 1906 and 1911 copies at Toronto Archives. If you know of a copy from another year, possibly in your own collection or for reference at a local library, please let me know!