fender tag Decoding Values

where they are getting the information

sifting through individual option codes from scanned books at hamtramckhistorical.
Like YY1 wrote, go here The 1970 Hamtramck Registry Library Page (1965 - 1969)
Then look through the dealer info like the data book and pocket guide.
This is the type of factory lit that would be considered primary source.
IIRC some fender tag info is in the shop manual and parts books - some years.