The seven-storey building at the corner of Ross Street and Third Avenue was the home of the W. W. McBride Paper Company. Multiple layers of painted signs make it hard to read any one of them, but the name “W. W. McBride” is clear enough.
The Century Cyclopedia of History and Biography of Pennsylvania (1904) has an extensive biography of William Wilson McBride, and we quote the part that has to do with the firm and the building:
In 1890 Mr. McBride bought a half interest in the well-established paper business of Morrison, Cass & Company, of Pittsburg, which owned large paper mills at Tyrone, Pennsylvania. The other half interest was retained by John Cooper, of Pittsburgh, who had been a member of the original firm, and the business was carried on under the name of Cooper & McBride. After four years Mr. McBride bought out his partner and became the sole proprietor, operating under the title of W. W. McBride & Company. In June, 1902, the business was incorporated as the W. W. McBride Paper Company. During 1901 he built a fine seven-story brick building at the corner of Ross Street and Third Avenue, containing the offices, sales department, and storage rooms.
By 1923, according to the Pittsburgh Historic Maps site, the McBride Building had become the Bowman Building, so these signs must all date from before that time.