Those are rare, they were minted to commemorate the Cincinnati Bengals winning the superbowl. I think
I am not sure if it is a pen or just something that was stored with the coin, but it is not a result of anything the mint did. The striped coin from the mint are a result of a poorly mixed alloy with parallel stripes (as a result of the milling). See http://www.cointalk.com/t65353/
I am not sure just what your definition of rare is. In some dates, they may be the majority of the coins, but there are other dates I am not sure I have ever seen as a woody. Implied with rare is valuable. Here, most of them actually sell for a discount because most collectors take that as a negative. And I have seen several where I think I agree with them.
That doesn't mean its worth a buck... just that a sucker is willing to pay a buck. There is a difference....