When we were about to give up the search, we found it! It was easier than it looked, it was being auctioned at eBay. Funnily enough, it was there before the 4x11 Lost episode was aired.
Now the thing is... the auction for the Mystery Tales 40 finishes on May 16th, we don't know if we're going to be able to win the item, because now the price is about $130 but, it will definitely raise as the deadline gets closer.
The auction says nothing about it appearing on Lost, but we're sure there are many Lost fans out there that will bid high for this item, we all know what happens in the very last minutes of an eBay auction. We're going to keep an eye on it, anyways. We really need it, the hidden (is)land is waiting for us!