The problem with many of Johnson's original manuals was that many of the page sheets were printed on acidic-type paper. After 60 plus years, sheet color turns to a darker color making "good" scanning much more difficult. Plus, it was quite common, especially with acidic paper, to have print bleed-through on double-sided pages. If you scan at too high of a resolution, you not only scan the near side print but, depending on the extent of the bleed-through, you will also replicate the bleed-through print.
The printing company that Johnson used had the tendency to print to within 1/8 inch of the left or right paper edge. With most of today's digital scanners, there is normally a default 1/4 inch gutter edge around the entire sheet (no print allowed). So, with today's scanners, if you're not careful or aware, scanning can sometimes cut off the last one or two letters in a sentence or word. If you're good at manipulating these anomalies, you can avoid these pitfalls.
For some, free stuff doesn't mean great quality or completeness.
It is what it is and it's free!
