Finding the Serial Number. Ices 003 class b motherboard. Finding the serial number on Estey reed organs can be challenging. Ned Phoenix, an expert in reed organ restoration, has provided a guide for locating serial numbers on Estey reed organs and melodeons. Occasionally the serial number on an older instrument is impossible to locate. If you are trying to determine the age of an organ with no serial number, please feel free to contact the museum for assistance. Make sure to include a photo of the organ. What you have is the Estey Junior organ. See number 0353 in the database on my website www.reedorgan.info. The serial number dates to between 1941.