Your best bet would be the Schomburg Center for Research in Black Culture in Harlem, which is one of the research libraries of the New York Public Library.

Unfortunately, I don't see any interior photos in their online digital collections, but you could try contacting them with your inquiry.

The New York Real Estate Brochure Collection of the Avery Library at Columbia University has a collection of digitized floor plans, which might help you with the overall layouts but not the furnishings.