Joel, thanks for showing the two actions together, you can clearly see where there are differences. As well as the three things you mentioned there are also a few others.

The trigger guard is wider and not shaped
The rear tang has no sweep
The front of the floor plate is thicker
The bolt shroud is heavier

When you add it all up it obviously make s a big difference.

Are there similar differences with say the Magnum actions as well.

Matt.