Knowing the building practices of the luthiers behind the guitar, what years major changes in the building process or materials occurred, and knowing the difference between authentic materials and cheap, almost identical substitutes will equip you with the knowledge you need to steer clear of the fakes.
The serial number represents the date and time your guitar was built, in a specific format.
Electric Sound Products was opened in 1975 by Hisatake Shibuya in Japan.