Thunderbolt10031 wrote:Well in order to tell what model it is Federal usually puts the year the product was made in the last two characters of the serial number. For example, lets say that a Thunderbolt was made in 1974 and you didn't know what year it was made on. You could look at the last two characters of the serial number and it will tell you that the Thunderbolt was made in 74.
This is not always the case with older federal products typically if there is a date code your serial number usually ends with the last three characters consisting of a letter and two numbers. So if it ended in say "H81" it would be 1981. If it does not have that kind of ending then the end of the serial number may not be the date of manufacture. I'm sure "holler" or "murrfarms" or any of the other guys who have done a good bit of research on this can give you a more complete answer