Ron,
I went out to the barn and looked tonight like I should have done to begin with instead of going from memory. You're right that they're not straight cut, but they're not hypoid either. They're spiral bevel gears. I'm basing this on the 125 transaxle I have the cover off of in the barn.
Spiral gears are the bevel equivalent of a helical gear. The difference between spiral and hypoid bevel gears is that spiral gears' axes intersect each other; hypoid gears' axes are offset.
You could flip the carrier with straight, spiral, or Zerol bevel gears. If you try to flip the carrier on a hypoid gear set it will off set the pinion axis to the wrong side of the ring gear axis and they absolutely will not mesh.
Hypoid gears are stronger loaded one way vs. the other, but is not like they're weak in reverse. Most 4wd front axles have hypoid gears running on the back side of the teeth. With straight bevel gears, there's no disadvantage one way or the other. In the case of spiral and Zerol bevel gears, there's no practical difference, and if there's a theoretical difference it isn't worth talking about.
Jerry