With the tag showing a 21,000 lbs gvw that means it's an S-69 model. That matches the 261.5 inch wheelbase shown on the tag. It also makes it have the 7,000 lbs front axle and 7,000 lb front spring capacity. The rear axle capacity is 15,000 lbs and rear spring capacity is 17,500 lbs. all of which look to be the largest in the Bus models.
This still doesn't match up with the VIN decoder on the chevy60.com site. Please educate me if I'm wrong.
