The online Jack Kirby Museum has posted a number of these, including several lost pages of a Hulk tale that were literally saved from the dustbin by Marvel scripter (and Marvel publisher Stan Lee's brother) Larry Lieber.
In his testimony, Larry says:
"... Jack Kirby came out of Stan's office from -- and from the direction of Stan's office. He may, probably, he had come out of Stan's office, and he seemed upset. And he took the drawings, he had these drawings, he took them and he tore them in half and he threw them in a trash can, a large trash can.
"And I, since I was such a big fan of his, I knew that at the end of the day, they would be discarded, you know, and would be trash. And I -- I saw it as an opportunity to have some of his originals to keep, to look at and study, and so I took them out of the trash can.
"And there were other people in the office, but nobody else seemed to have noticed this, which I was glad about, and I just took them, walked over to where I was sitting and put them in my case. And I took them home and I taped them together, you know, I taped them all, and I kept them and I've kept them all these years to look at them and, as I say, to study them."