body panel help

In my '69 Barracuda vert I am replacing both frame rails. In between the frame rail and the rear valence there appears to be a panel of some kind that is mostly rusted out and I'll need to replace. Not sure what it is called. Looks like the rear of the frame rail is welded to it. Can someone help? Is there a parts diagram that would help out? Thanks.
Here you go.

A-body rear crossmember.

Here's the ABS Part number.

1967-72 DODGE & PLYMOUTH A-BODY REAR CROSSMEMBER