Serial. 1961–62, No number. 1963, No Number – 7900. 1964, 9XXXX – 33449. 1965, 108532 – 259XXX X's were not actually used in the serial numbers.
I think in general serial numbers do play an important role in the commercial market especially electronics and other high end items. In the 60's Insurance.
Regardless, there are three different Ludwig Serial Number dating guides, drum badge dating guides and all sorts of Ludwig History. Just follow the links below.