Part numbers, IBM Correcting Selectric III complete

p>I am currently doing research for an original article proposing a neo-Victorian-style computer workstation: Among the items referenced in the research is a popular office machine from the 1980’s, the IBM Correcting Selectric III, Model 670X. Since the 1960’s, International Business Machines Corporation had used 7-digit (now 7-character) part numbers for everything up to complete assemblies, e.g., 5170339 for a later-model Personal Computer AT, or 5251021 for an EBCDIC data-processing smart terminal. Online PDF’s of Service Manuals for the IBM Selectric family of typewriters mentioned all individual components, but no part numbers for complete typewriters.

As I understand things, IBM probably reserved several part numbers for Correcting Selectric III packages preconfigured with specific typeballs. What would the IBM salesman have worked from to take the equipment order? That is a critical missing piece of the puzzle, as it has the part numbers for the packages. Any help securing this information would be appreciated.
@GibsonEssGee The Catalog cited, which refers to the Selectric Typewriter Adjustment / Parts Manual (IBM P/N 2415939) on the front cover, was used by the Service Technicians and has part numbers for components and upgrade packages, but not complete typewriters. The part number for a complete Model 670X is NOT to be confused with that of the Cover, Complete, Correcting Selectric Model 893, Onyx Blue (IBM P/N 1287670).

I also found no reference to complete-model part numbers in the Operating Instructions, IBM Selectric II Typewriter and IBM Correcting Selectric Typewriter (IBM P/N 1206423), although a list of expendables (with associated Part Numbers) is listed therein.