You didn't read the ad correctly, the ad was a misprint, or someone is lying.
There are no such tractors, at least not in the USA. If you are not in the USA, please indicate that when you post because otherwise we will give you a hard time about making up tractor models that don't exist.
Could the ad have said 756 or 766? Both tractors are roughly 75-80HP, and will run a smaller round baler.