One of this writer's favorite U.S. coin series, the proof No Motto Seated Quarter is a very rare type.  None of the issues in this series can even remotely be described as common, struck as they were during an era when numismatics in the United States was in its infancy.  The 1851 is currently unkown in proof, and the remaining issues exist in very small quantities.  The 1842 Small Date is a proof-only delivery.