I changed the one on my 83 shovel an 94 fxstc an just marked the title inaccurate mileage when I sold it....it hurts resale some but you do what you gotta do.
Considering the age and the mileage, an odometer that isn't accurate would be the least of my worries selling this bike.
Going by my service logs I "rolled" the odometer back to "zero" the second time last October. Figuratively, anyway, as the third speedo was reading around 63,000 miles at the time.