For old guitars we can only know the exact data reading the ESP warranty card (when there is), or unscrewing the neck (if the neck is bolt on) and read under it becuse probably theres the data write on pencil). I keep record of this data in order to try to deduce other correspondences. ESP Guitar Company says: 'Unfortunately the factories at ESP Japan have not kept a consistent and sensible serial number tracking system in place over the years. This has resulted in alot of confusion, and.