Artillery dial sight No 9 Dial sight in original steel case - Artillery and Self Propelled Weapons - MILWEB CLASSIFIEDS Panoramic Dial Sight No. 9 Mk 1, 25 pounder gun - Militaria - Collector's Source, Military Collectibles Online
Apparently used as sights on a number of things
It may have only been manufactured in Canada, not specifically a Canadian product. Lots off stuff was contracted over seas during the war.