Yes, hard to tell for sure from the picture, but that extra grove on the crank pulley is a clue. Try using a straight-edge like a yard stick or carpenter's square to check for alignment.
Also worth checking that the "accessory" that the belt is turning is working correctly. If, for example, the hydraulic pump is seized, the belt will try to turn, be unable to and just sort of slip. It'll smell and squeal. Symptoms could be worse at high RPM's (like highway speed) or worse under accessory load... like when the fan tries to start turning when the thermostat opens.
I don't know the 7.2 Fuel Saver. Looks a lot like the GM 8.2 V-8? Unfortunately, if it is the 8.2, I have some bad news for you....
I think the "eccentric" pulley is just a tensioner/idler.
Regardless, great looking bus!