Hi Jerry, I've had time to knock this out this evening with the superimposed images you requested.........good idea!
Actual pictures of both 1875 'Cannon Ball' coins are at the left hand and right hand ends, both shot at the exact same 100x magnification, and identically positioned.
The unusual (italic looking) 5 picture has then been over-laid onto the normal 5 picture.
Looking from right to left, it has then been gradually removed, 10% at a time, using the software transparency feature.................to slowly reveal the normal 5 underneath.
As you suspected, it is pretty convincing that the unusual looking 5 is NOT an altered die......... even though at first sight it would seem to be so.
I guess it is just a late strike of this variety, with part of the top of the 5 now blocked out.
Hope the pictures are clear enough; I had to resize to stick within the 500K limit!!