We knew before we put together the manuscript that we had too much material for a single book, so we set out to put together a "balanced" volume. And by balanced, I mean balanced between classic images that fans expected to see versus images that they hadn't seen before, balanced between known deleted scenes versus new ones, and so on. Ultimately, we had to make a lot of tough choices, so a lot of nice material got left on the cutting room floor... again.
We thought the Peter Kirk deleted scene from "Operation -- Annihilate!" was pretty well-known, so we chose to not include it. That freed up some space so that we could show a new deleted scene. If we do another volume, however, we'll try to include it.
Of the deleted material that didn't go into the book, about 1/2 of the scenes and trims are from episodes that are in the book. For example, we have more from "The Enemy Within," "Dagger of the Mind," "Court Martial," etc. The other half of the remaining material is from episodes that aren't featured in the book, e.g., "The Man Trap," "The Naked Time," "Obsession," etc.
Btw, speaking of the deleted scenes (and trims) in the book, there are more than 37 episodes represented. We tried to use images from them in the BTS and Bloopers sections, so there are a few there, too.