I wouldn't at all be surprised to find that many really "cool" things were taken by staff over the years. However, there are two levels of "cool" here.
1. The undeniably rare and valuable... such as the first pressing of Lynyrd Skynyrd's "Street Survivors" album which has the group engulfed in flames on the cover. After the plane crash that killed group members, that cover was withdrawn and the LP came out with a different cover.
2. The hard-to-find ones that will excite, if they get into the proper hands. For example, there was this all-female rock group from the mid 1970s called Mother Trucker. They were from England and signed to Ember Records there. Their record(s) was/were released in the U.S. on Paramount/Ember Records. I've got a promotional copy "45" by them with a picture sleeve. It's really good. I've never seen an album by them. That would be an exciting find for me if, in that massive collection, there was a Mother Trucker album! Something like that may have a good chance of being there, and still in good shape because since it wasn't a "hit", it wouldn't get used that often, if at all.