Of course I've heard of the
Dead Sea Scrolls. And of course they were copies. But before the printing press came about, copying texts was very slow and expensive (according to
Nate Silver in "The Signal and the Noise", a single manuscript would've cost a Roman about $20,000 if you translated that to "today's currency"). So it's unlikely that many copies were in circulation, and as I said before, a peasant wouldn't have been able to read the bible even if he had it in his or her own language.
While I agree that the Catholic church is "changing constantly" in some way, it seems unlikely that they used to be preaching "faith alone". Religions have a tendency to resist change, and when they do it seems to be in response to the in-tenability of their beliefs (such as the Catholic Church's current acceptance of Darwin's and Galileo's theories). In fact, given the specific arguments Martin Luther had with the Catholic church, it's obvious that they rejected "faith alone" during his age. Do you think that this stance of the Catholic church had been adopted within 100 years before Luther, or had at least one or two generations passed since the Catholic church held this stance, assuming that they ever did?