This is a pretty general answer, but just try to think of what would be the most helpful to your customers, in the absence of the search engines. Does "leather book binding" need it's own page to best communicate to your customers? Is that the most natural term, the one you'd use if you were talking about book binding with leather? Then go for it.
If "book binding service" is different enough from "print and binding" to warrant different content, then go ahead and give them each their own page. If not, then don't worry about it. The search engines are advanced enough to pick up on intent and synonyms to a reasonable degree.
I recommend it all the time—like, I think I recommended it to someone less than 5 minutes ago—but I love Cyrus Shepard's "Keywords to Concepts" for how well it explains the concept of topical keyword research. If you haven't read it, it may clear some things up for you.