My thought is that this is normal 'shading', not damage. This doesn't look like a big deal to me, but a result of the natural 'step' and minor deformations (normal in light stress skin birds) where the skin lap joint occurs.
Had there been visible damage from a hard landing, I'd expect to also see evidence of diagonal wrinkles in the open-field areas of skin between inner bracing - that is a common failure mode in semi-moncoque designs where bending loads were excessive - especially were the forces large enough to cause what has been speculated here (a 'gap' at a lap joint). All MHO, of course - but I don't agree that we're seeing 'damage' here. I also doubt Earhart would have permitted a cameo shot involving any hint of a damaged Electra, somehow, at least in that situation; the Luke field photos were unavoidable - but the 'hard landing' in Miami surely wasn't much publicized (or desired to be, logically).
The "damage," if that's what it is, is not particularly apparent to the layman.
The 'vertical bracing' evidence just found on 2-2-V-1 (with no fastener holes - odd) is peculiar. The skin had to have been pressed fairly hard against some sort of a flange to get that 'mark' - doable by any number of means of applying broad, blunt force which wouldn't necessarily create a major crease if broad and blunt enough, but enough leave this tell-tale evidence, I suppose.
However the imprint happened and whatever the reason the underlying structure wasn't riveted to the sheet, it's presence is significant. Follow me on this.
First: So far, Jeff Glickman has been able to confirm the presence on the patch of four of the five rivet lines on 2-2-V-1. Three of the lines (1, 3 and 5) align with known stringer. locations. Line 2 appears to be an added stiffener. Line 4 falls within a dark area of reflection on the patch and is much harder to see. If it's there, it's another added stiffener. In any case, 4 out of 5 ain't bad.
Second (and this is really neat): We know that one edge of the artifact failed from metal fatigue after cycling back and forth against a rigid underlying structure. Let's call it the "straight edge." With the artifact accurately scaled and overlaid on the photo of the patch so that the rivet patterns line up we can position the artifact so that the straight edge is up against the underlying structure that the window was riveted to. (Note that the window was not riveted to the bulkhead at Station 293 5/8 but to a structure about an inch or so aft of that bulkhead.) If we place the artifact there the mysterious vertical imprint lines up exactly with Station 307 where there was once a vertical structure before it was cut to make the hole for the window. The skin around the rivet at the top of the imprint tore when the rivet failed, possibly because the rivet was attached to the circumferential structure at Station 307.
Of course this could all be coincidence.
It looks like the patch was an attempt to restore the structural integrity of the fuselage in that area. Why the vertical member never got stitched to the patch is a mystery. Maybe they just ran out of time. I've been able to establish that the photo of the airplane in Miami with the window still in place was taken on Saturday, May 29. The window was gone and the patch was in place by the time AE and FN left early on the morning of Tuesday, June 1st - so the modification to the airplane was done sometime on Sunday or Monday (Memorial Day).
