As an aside, I also clearly remeber the experimental schemes that Pan Am applied to 2 B747-100s in the early 1980s before introducing the billboard scheme...
The first had enlarged PanAm titles in blue, with the cheatline lowered to accomodate this. The second scheme had the now familiar billboard PanAm titles in their final size and location, but the cheatline was reatined both fore and aft of the name.
Luckily there are a few photographs of each in the database;
Happy memories of Pan Am - my first Trans-Atlantic flight, Heathrow-Miami in 1988!