"If those of us interested in books (and other things) as artifacts, not just vessels for an abstract text (or other meaning) have learned, often by sad experience, it’s that we can’t tell what aspects of a physical object and its pieces and their relationship may turn out to be of value in reconstructing the historical record and better understanding what went on in the past.

One of the best examples of this is provided by a courageous publication by Nicholas Pickwoad, "Swaffham revisited: A review of the earlier conservation of books in the Swaffham Parish Library,” in which he examines work he had done twenty years previously and documents what rebinding and other conservation work had destroyed or obscured. The work he did was perfectly acceptable at the time, indeed recommended practice. The essay should be read by all curators who think of rebinding old books, or otherwise altering historical artifacts, as well as anyone else interested in the preservation of artifactual evidence. Happily, the essay is available on the internet: http://iada-home.org/ta99_097.pdf "

John Lancaster in EXLIBRIS-L

See also

https://www.academia.edu/1834228/_Physical_Evidence_and_Manuscript_Conservation_A_Scholars_Plea_