Dave,
your musket is probably the M/1849 German Federal Navy Rifle. These rifles are marked on the lockplate S & C/ SUHL with an eagle and anchor mark. They are considerable shorter than M/1809 UM or M /1839 Prussian muskets. Beside this there are also M/1809 UM which are marked with the Würfflein address (see Noe/Yantz, Firearms from Europe. Check Your gun in length and lockplate markings and I can give You further informations.
Best regards
Marc (Germany)