It might be caused by carriage jump but in a different way we now see.
And the far-left "A" just looks like the carriage jumped the margin when it was returned.~Alan
The days when Sholes penciled "Is this paper thick enough?" and just ahead when he had typed out this letter to Densmore on October maybe18th, 1869,,
In those days, it seems they didn't have side moving roller carriage in longitude along the line out-printing mechanism.(Later they had as on Scientific American August 10th 1872.)
The mechanism they had a patent as cylindrical platen earlier was for moving in circumferential direction along the circular out-printing on the rotating cylindrical platen,
not for longitudal direction line printing.
If using their early cylindrical platen mechanism, then the incidents like carriage jump would rare happen.
And to roll up the cardboard might be hard to bend to set on the platen.
Sholes typed a letter to Densmore. Oct.eight inch thick cardboard Sholes Densmore - Google book search
28 is not be accurate, and might be18, 1869, on cardboard an eighth of an inch thick, and added a penciled note in which he triumphantly asked, " Is this paper thick enough?
So I guess the carriage jump might happen on an old model machine which made over adding with mechanism changed to like ink-ribbon winding in downward, or so.
But I should know more detail how paper had attached round on the cylindorical platen on these days of Sholes.