I agree that the street in the Depression era looks in much better shape than now. I don't live near the area but what I always find striking about older buildings is the level of decoration that went into even the industrial building seen in the photos, window frames and cornices for example. The apartment buildings are typical of the '70s and '80s, plain boxes that would even bore a communist architect.
Back to the building in question. In a city that has torn down buildings to widen Dundas St. or completely demolished a neighbourhood for the Gardner, why was this building kept? Why was a door and windows put in the abutment when, if a basement was there, a wall could of sufficed? The windows themselves are interesting, they are too high to be viewed through from the street and probably as well from the inside. Could this be an Icehouse?