It's interesting to me how we, as humans, ascribe more value to things based on previous ownership. Why is a watch worth $35000 if President <X> owned it, but only $350 if not? Is it not the same watch?
There's a lot of emotional weight in the article, "The". A watch is an interesting thing from a functional perspective, technical perspective, an artistic perspective, and a broader historical perspective. But it's an implicit consignment to a relative definition. A watch is interesting amongst watches, perhaps. Comparable between watches. Valued according to the value of other watches.
However, when you can promote that A to a The, now the thing stands as an absolute in the course of history. The watch that Buzz Aldrin wore on the moon. The pen that signed the surrender of Japan. The Cullinan I Diamond that was cut with nine sibilings from the greatest raw stone ever discovered, and set in to St. Edward's Crown. The nature of the item itself becomes second to the story and the lineage associated with it, and its value ceases to be a function of what the thing does does, and becomes one of what it has done. Omega watches are interesting and technically impressive. But if a Seiko had gone to the moon on Buzz Aldrin's wrist, it would be worth just as much.
On the off chance you're interested in that particular pen, there were actually several of them. I collect fountain pens as a hobby, and ones used to sign historical documents are of particular interest to me.
The founding fathers have a mythical status in the US. Many observers liken it to religious worship (google "civic religion") with the founders akin to the original disciples of the faith. America's early puritan, Protestant, roots also give importance to books. The act of reading books and then writing about them is almost a form of prayer (see the Latin v. English bibles debate). So a book owned by a founding father is precious. A book modified and written upon by a founding father is a sacred text.
In addition, the american legal tradition gives great importance to the concept of original intent, understanding the mind of a document's author. Important documents such as the US constitution, and therefore many modern day legal debates, are understood through the lens of historical context. Knowing the books read by those who wrote such documents gives one argumentative power in the modern context. So these sacred books are a source of modern day power, adding to their perceived value.
I want to know why he moved the first pages to the middle. Is that some masonic thing?
It's not the item you're buying in that case, but the emotional connection to the previous owner.
I had an opportunity to buy a Parker 51 (fountain pen) once owned by Oskar Schindler a while back. I passed on it because it was part of a larger lot at auction that I didn't want, which went for more than I was willing to pay for the pen alone.
I've been looking for years for a pen that I've seen in several photographs of Kurt von Hammerstein-Equord, but I've yet to come across it (or any of his personal effects). I'd pay a great deal more for it than I would for an identical pen without that provenance. I mention it here because who knows? Someone might know where it is. His family moved to SoCal after the WW2, so it's within the realm of possibility.
Additional meaning and connection are emotionally valuable (especially when rare or irreproducible).
I assume you’d prefer to have Newton’s Principia, Turing’s papers, or your grandfather’s watch vs. a reproduction, even if the practical value of the information is the same.
