Someone owns the copyright in the photos
Ancient Greek art is not subject to copyright because a) there was no copyright law in Ancient Greece and b) even if there were, the works have long since entered the public domain.
However, photographs of art (or anything else) have their own copyright and ones dating from the 1970s will not enter the public domain for many, many years.
Since you are publishing this online, technically you must comply with copyright law in every jurisdiction where this can be accessed. While you may be able to successfully argue fair use in the United States, this is not fair dealing or similar provisions in other jurisdictions.
To be safe:
- Get permission from the copyright holder (their name should be in the book);
- Use public domain photos from a different source; or
- Go to the museum and take your own photos.