>> They all looked in excellent shape and had been kept in sturdy record "book" made specifcally for 78s, in which each 78 slid into a sleeve with a hole so you could read the label. <<
That "book" is called an album, and was the origin of the phrase "record album", akin to photo album.
That "book" is called an album, and was the origin of the phrase "record album", akin to photo album.