Paint code “Unknown at this time “

Agree with above. Butterscotch came out in 69 as code 96 or 99, as a new late year color.
It disappeared for 1970, but when it came back in wide use in 71, it was EL5, , E, because it was an unchanged color from 69.
So... your 1973 F8 green will be different from earlier (or later) versions of F8.