In addtion to the advice already given, there is another option that you could use to find the seller.
First of all, do a search for the item as if it was still for sale. When the search results come up click on the "Completed Items" option on the left hand side of the screen, and it will show you a list of all of the recently expired listings, whether the item sold or not. If the price is in green then the item sold and you won't be able to buy it, even if you did contact the seller. If, however, you find the item and the price is in black then the item didn't sell. Click on the advert and look for the seller's User ID. You don't need to click on the "See Original Listing" link - just click on the seller's User ID and when the next page loads up look at the top right hand corner in the white box containing the seller's DSR's and click on the "Contact Seller" link. You can then send the seller a message to ask whether he/she would be prepared to relist the item for you so that you could purchase it. If the seller agrees to do so then you should be able to purchase the item when the seller lists the item for sale the second time.
