Yikes, at least I found out before I tried a reveal! I'll never buy pre-owned LV again because I don't trust my own judgment. I actually compared my fakes to my friend's authentic ones (bought in the LV store) and thought mine looked better. And yes I did toss them when people here said it would be wrong to use them. I have seen reveals closed because they were found to be fakes and felt so sorry for the owners.
Editted to add I bought them in good faith at a consignment store, not intentionally.