How difficult is it for someone to change the odometer numbers on a 450 sl ?

I ask because mine reads 38699.0 miles. The condition of the car would lead someone to believe that it has 138699.0 miles, or more. The odometer is working as far as I can tell, but then I have only put a few hundred miles on it since I bought it.

The last piece of paperwork that I have from a repair was from 2002, and it had the mileage listed at about 33000. Is it possible that this could be actual miles, or could it have been adjusted somehow?

__________________
Tim "Furndog"
______________
1977 450sl How Cool!