@NickPoole1 We have been working on such a model for museum collections including books and archives. I spoke about it at the Collections Trust conference in Leicester in September and also at a workshop on the national aggregator in Johannesberg. I would love to share my ideas with you.
Well worth reading, and for us to determine at which point in a search should consider items as "lost", and what creative explanations we can conjure up when they are found in the museum. I am wondering how acceptable the excuse "the label was wrong" will go down.