Two of the tires keep loosing air
Looks to be an earlier '68 as it has the RF style steering wheel with the large center cap. The tag would either be on the pedestal below the dash or on the right side of the tractor which is not in any of the pics.
One more thought: Those tires are made of a softer compound than the other types available. If you plan on using it regularly either keep it off of concrete/asphalt or swap on different tires. Restoration guys want those in good condition.