We do not have means to check the ECM. However, I do know the background on the bus and the bus' good condition confirms the odometer. Another clue, is the brake pedal. This rubber pedal looks like it has 78,000 miles on it. Moreover, I do know with confidence that the odometer and hour meter parallel the life of the transmission, motor and chassis.
The transmission is a Allison AT-500 Automatic 4-Speed