I agree, this has to be a work in progress. If you try to incorporate everything in the first pass, it will never be complete. As you said earlier, baby steps. The other problem is that if you try to include too many key categories in a spreadsheet, it quickly becomes unreadable. The body code can always be added later by copying a row and added two or more body codes. ie. 70 sport fury 2 door and 70 sport fury 4 door, but I think it's easier to simply start with sport fury 69, 70, 71.I personally would like to list it by models.
e. g. Newport, Newport Custom, not...
Newport 2 dr sdn, Newport 4 dr sdn, Newport 2dr hdtp coupe, Newport 2dr Fast Top.
Then we get into body styles which thenyou could break down into infinitesimal increments which will cause even more arguing. Reg. vinyl top, Gator top... Ugh...