Doug suggested Hollar doors. Bingo!
It took me just about all day but I finally found an article in The Banker’s Magazine, volume 80, March 1910, page 492 that discusses unique safe deposit vaults of the era. The first vault discussed is the Carnegie vault. The article states that the company organizer, Charles C. Dickinson, “… enlisted the services of William H. Hollar, of the Hollar Company, as designer and engineer of the vaults.” The article includes some nice photographs, including one on page 494 that was printed upside-down.
The Banker’s magazine - Google Books
The Carnegie Safe Deposit Company was closely tied to the Carnegie Trust Company which failed in September of 1911 after about 4 years in business. They had no affiliation with Andrew Carnegie and used his name without permission, and failed due to some questionable transactions as well as the poor luck of being mentioned alongside some shady characters.