French Chocolate Opera - Lot of 13 Opera Singers Photographs Autographs Actors - Letter A slight paper loss and rust

slight paper loss and rust on borders but image is clear

Maria Callas in the title role

As well a printed letter of thanks

Double signed album page of German soprano and mezzo-soprano Anna Hildach (1852-1935)  and her husband

and was also a teacher

French Chocolate Opera - Lot of 13 Opera Singers Photographs Autographs Actors - Letter A slight paper loss and rustLof of 13 unsigned vintages "French Chocolate Opera" trade cards by Guerin Boutron & Grondard companies depicting famous opera singers of the late nineteenth century and early twentieth century, including Breval, Caron, Cesbron, Duse, Lasalle, Litvinne, Nuovina, Rejane, Renaud, Sanderson, Talazac, and Van Dyck. Each one's size is 2. 4 x 4 inches, in very good condition or better. SOLD ONLY AS A LOT, NOT SOLD SEPARATELY.