Hello, I am relatively new to collecting Russian imperial coinage and was wondering the authenticity and if the coins would be worth purchasing or not, they include a 1740 Moscow mint Tsarina Anna 1 ruble, 1748 St. Petersburg mint Tsarina Elizaveta, 1757 Moscow mint Tsarina Elizaveta, 1828 St. Petersburg mint Tsar Nicholas I, 1831 St. Petersburg mint Tsar Nicholas I, lastly 1876 St. Petersburg mint Tsar Alexander II. Thank You!