The other slot is for a 1965-D, but that is a coin that was never actually minted. The reason there is a slot for it is because this album was produced before 1965, so at the time they did not know there would not be a 65-D. But with all the high grade coins in there, including the 3 steel cents being in high grade shape, it really is such a tough set to put together! As you can see from the pics the coins are in amazing shape, and as mentioned most of the coins, especially the ones starting around 1951, are all in high MS uncirculated condition.
None have any major damage and none have been cleaned. This is an amazing investor-level set for any collection.