My Buddy has a RSTD with 60k on it and he consistently tears me up on mileage. If I get 42 he gets 45 on the same trip, same roads, same gas, and generally same riding style. The only difference I know of is he had his carbs rebuilt.
35mpg is unacceptable on this bike. I have a 2000 RSV and even with 2up riding and full luggage at 75+mph I can get 38-39, solo is 42 all day long, every day.