A-Body Shock Tower Question

I have a question about the very top of an A-body shock tower. I have a nice set of frame rails I got to repair my '68 Dart. Once I have my front sheet metal off and can inspect the right front frame rail more thoroughly, I am leaning towards just replacing or grafting the front section on to my rotted left frame rail. If I find major damage on the right one, I'll just replace both.

My question is, does anyone know the exact reason for the ledge at the top of the shock tower (Circled in the attached generic picture)? Is it just a support for the inner fender apron? The ledge of the shock towers on the nice rails I have were both clipped off apparently when the inner fender aprons were cut. It looks simple enough to graft new ones on, fortunately the tops of both my shock towers are fine. It would seem easier to just graft the top ledge back on instead of try to replace the whole shock tower.

Any thoughts?

Thanks in advance for all the expert advice.
K.C.