1967-69 Air Cleaner service instruction silkscreen lables are curved, starting in 1970 the label is straight with changes to the wording.
The pic below is the correct original label used on 67-69 Camaro Chevelle Nova and Corvette, this label is on an enclosed air cleaner
with a chrome lid from an all original 1969 L36 427 Impala built January 1969 4th week.
The first two words are missing on the first line which should read "AIR FILTER" followed by "SERVICE INSTRUCTION"
This car belongs to a friend who bought it from the original owner 15 years ago.