Shanks, I am unfamiliar with the term "silver service" in the sense you indicate, but it strikes me that it is a term invented by the caterers to market Service a la Russe.

I think you will find that "cutlery" refers to knives, and - if a person does not speak of "silverware" regardless of the metallic composition of the item - "flatware" refers to non-silver eating utensils.

I think you might find some prior discussion of this from a couple of months ago, assuming you are better with the searches than I.