
I usually keep stamps regardless of condition. I had to make exception in one case. I had a box that was used to ship ballet slippers to the US from Belgium. The lid was so covered with low denomination King Baudouin stamps that from a distance it looked like it was gift wrapped.
That lid plus a lot of duplicates and some comic books were soaked in sewage when my basement soil pipe split. My only regret in throwing the stuff away was that I didn't photograph the lid when it was still "alive".
The image is the corner of a different box that I was able to save because it stuck up from the slop like an iceberg.