The only input I can give you is that the driver side (picture on the right) with the hole in it is probably for a 4x4 truck. 4x4 trucks have the steering column on the outside of the frame, and the large hole is where the steering shaft would pass through the splash shield.

I've never seen a short passenger side splash shield. Don't see how that would work unless the inner fender had a different shape at that back corner. Gene