hi, I have bought a DVD of the seven samurai(The Criterion Collection) a couple of months ago used, and decided i wanted to back it up. when I loaded it up with DVD shrink there was an 'unreferenced material' folder. upon checking the folder i have found that it is the restoration demonstration. this cannot be accested by conventions means when viewing the dvd. the only way I can see it is through dvd shrink. I have read that these copies are very rare and very special. tell me, do all copies have this? and if not is it worth more? Thank You, I hope someone will give me an answer.