If they had the original "typewritten" document then wouldn't it still have indentations from the striker keys?
Yes!!
Yes, but I think they never had the original. We'll see.
Especially the punctuation marks and most especially the period, which sometimes punches a hole right through the paper. I have a very old Underwood portable I sometimes use and from time to time I have to adjust it for this and other reasons.
Also, as the typewriter ribbon gets worn, the print tone lightens, especially for those passages typed when the ribbon is near the end.
There are lots of other peculiarities too. For instance, in an old typewriter like mine, the metal characters wear down with age and do so unevenly. This changes their appearance in ways not casually apparent but which become obvious under close inspection.