1965 Dodge Dart Charger

…more than a decade after it was built. That's a lot of time for stuff to happen. I can think of at least two plausible reasons why an air cleaner service decal present when the vehicle left the factory might not have been present by the time your dad bought the car in 1976.

Possible, we have been in contact with the original owner recently of dads car, so I will send him an email and see if he remembers it, he might have pics of it when new for us yet if he found them. But, looking at the cover, there is no evidence of it ever having one, dads car was all original and never hot rodded, low mileage when he got it. Dad also has a pic of the engine from 1976, I will look at it closer and see what I can find.