Technically, inspiration refers to the process by which the Scriptures were given--"All Scripture is given by inspiration." In the Greek "given by inspiration" is one word, theopneustos, actually an adjective meaning literally "God breathed." So, inspiration is the process by which God gave the originals through human agency.
As you say, the basic doctrine is that the Scriptures were inspired in the original mss. However, I use the term inspiration to refer to copies, mss if you will, in so far as they are identical to the originals. I don't see how we can avoid using the term in regards to the mss. A document doesn't lose it's basic qualities by virtue of being copied. Translation, of course, is a whole new ball game, and I don't refer to a translation by the term "inspiration."