I should post also that the green paint on my 2009 military has gone to pot completely. Even though I keep it under a cover 90% of the time, and we don't really have winters where I live (one day of snow, low precip, I ride all year anyway), the paint and all the rubber are almost sun-white. The seat is white, dry, and cracked in places, the fenders and toolboxes are chalky, and the casquette could barely be called "green" anymore. In comparison, the gas tank, which I SPRAY PAINTED a year and a half ago with some Rustoleum 2x "hunter green", looks 10 times better than the rest of the paint on the bike.
And yes, I keep it properly washed, cleaned, and weather-proofed with the same stuff that I do on my horrible '80's car, and the car looks twice as nice as the bike. I think the tiniest amount of UV exposure destroys these bikes.
I still love it, and it adds to the "patina" of the bike when I lie and tell people it's 50 years old, but I'm seriously considering tearing it down and spraying it with the same stuff I used on the tank. The tank has held up wonderfully, even with gas spills.