Fender periodically produced technical information, distributing folders of such information to dealers. This would typically include lists of replacement parts, to allow easy and accurate ordering of new components. In some cases, as in the 1968 list below, circuit information and assembly blueprints were also provided. Something that made maintenance of Fender guitars very easy indeed, even to guitarists without the technical knowledge to describe the fault in their instrument. This level of post-sales care was rarely seen amongst other guitar manufacturers - at least to the level of detail given here. The Fender Duo-Sonic was deleted from the solid body range in 1969; these were the final parts lists for this guitar.
The Duo-Sonic sevice manual issued by Fender in 1968 consisted of five sides on a single folded sheet: cover; list of components - with part numbers and key to diagrams, (two sides); diagram of disassembled guitar; simplified Duo-Sonic circuit diagram detailing pickup and control assemblies.
This parts list is dated June 1969 - shortly after this model was withdrawn. These sheets are simply a list of parts and their numbers, without prices.