Don't know if this helps you guys, but the manual1 states

Quote:

VC-137 Expansion Model Expansion for 707-300 base pack. 707-300 base pack required. This part of the manual describes the VC-137 specific features only. BOEING AIR FORCE ONE AIRCRAFT The long-range version of the Boeing 707-320 intercontinental became the most commonly ordered version of the 707 airliner. Its fuselage was 8 feet longer than the 707-120 and its wingspan was 12 feet longer. With new turbofan jet engines, the B versions had a range of 6,000 miles, and in 1962, a 707-320B took over the role of U.S. government VIP and presidential transport, designated VC-137C. A second VC-137C was delivered in 1972. These were the first Air Force Ones. President John F. Kennedy's wife, Jacqueline Kennedy, selected the colors of the first Air Force One, VC-137C. The 707s served as presidential aircraft until they were replaced by 747-200s in 1990.

And the things Mark asked about are described as 78 EWSM aerial fairing while some other subtle things are mentioned, separating the Lady from the other variants.
So I think that if you just use the paint on the normal 707, you are close while this models enables you to be right on the spot.

So it's left to personal preference to buy it or not. Maybe Nathan can do some "presidential" variations of the paintwork on her.
I'd suggest the first one to have a really shiny and polished silver finish, like suggested by another forum user before.  :)