The number 1851 in the stock may not relate to a year but served some other purpose and may not even be period? Just like some specimens are stamped "SUHL" in the wood, the lock typically bears the date at the rear of the plate but there's no eagle or other stampings on the plate. All of the hardware is generally marked with a match-number, and sometimes there is a numeral 9 enclosed inside a diamond for a proofmark. However, much about these guns is not simply known because the province has been a part of East Germany for so many years, records from that era were virtually destroyed by the Soviets during the Second World War.