The Ottawa Public Library system has a wide range of Scott Catalogues available for both reference and borrowing—current year and the past two or three. The library has a standing order for new catalogues, so these usually appear soon after publication.
If you’re a member of the library, you can place a “hold” online and you’ll be informed when the volume reaches the branch you have designated.
There are complete sets of reference copies available at the Main Library downtown and at the Nepean Centrepoint Branch. These cover the current and past two years.
The Library also carries the Scott Specialized Catalogue of US Stamps and Covers, although there are only a couple of copies in the system and they are not reordered every year.
System-wide, the library has about 50 copies of the Unitrade Catalogue for borrowing, and an additional 25 for reference purposes. Roughly eight of those available for borrowing are the current year’s edition. It seems that most branches have reference copies of the current edition as well, but you can check this online if you’re a member.
The library’s collection of Stanley Gibbons catalogues is minuscule, but a search might turn up something of interest.