There is a posting on
ebay that proves once again the adage that you should buy the coin and not the slab.
https://www.ebay.com/itm/1842-ZS-OM...273720501556 As you can see, provided you own the correct reference book or have a very good memory, the coin in the holder is the rounded tail eagle type (1825 to 1842) which Dunnigan refers to as Rare yet the slab indicates the coin is the common type with the square tail eagle (used 1842 to 1845).
I have reported this to the seller because it seems only fair that he should have it re-holdered by PCGS before he sells the coin.
Here is the Eagle on the posted coin:

Here is the Eagle seen on the actual 1843 coin.

Anyone who can not immediately see the difference in the two eagles needs more study.