Why do some instruments have Getzen serial numbers and others do not?

Only instruments made by Getzen with a production date that is after the year 1963 have Getzen serial numbers. Many retailers sell instruments that are made by other manufacturers, and those instruments lack a Getzen serial number.

Before the year 1963, all Getzen instruments were made in one factory. In 1963, a serious fire broke out in the main production and manufacturing office of Getzen resulting in a major loss of products and records. The serial numbers on Getzen instruments before 1963 are no longer available due to this fire. The serial number is a useful tool in telling how old a Getzen instrument is.