The International Library of Music, Complete Set 15 Volumes. Piano Books
There is a name written on the inside of the front cover of each book that was marked over with black marker. There doesn't appear to be much if any other writing within the books themselves. The bindings show some wear on the outside, especially near the bottom. I'll add pictures of the outsides of the books/bindings, as well as a sample of interior pages. See photos for condition details.
Please feel free to message me with any questions.