A somewhat ironic placement of this DISCARDED stamp. I suspect every institution has sold, discarded, or recycled books in their collection, often quite quietly, not just the NY Academy of Medicine. I’m amazed how many books I have worked on that were deaccessioned at some point in their lives, then recollected, once again deemed valuable. What is considered a rare book changes. I’ll lay good money that a lot of currently “non-rare” books will become rare at some point in the future. Will all paper based codex books be rare someday?
Peachey Conservation 
Perhaps we need our own rubber stamp which says ‘’reclaimed’’- I have Harrison’s book as well as all of Pfleger’s books on binding, all were tossed. As least they were not ‘altered’.
Yes! Could be a fun exhibition – books about books and bookbinding that have been discarded…. and reclaimed.
I know I have a few.
I’ll bet you do!