Hi Micaela,
If the vehicle is 2023.2.1.A, I would recommend accessioning the ignition key as "2023.2.1.B" so that it is obvious the key is a "part" of the vehicle. If there are multiple keys – or other separate components to the vehicle – I would continue numbering them sequentially with letters (B is the first key, C is the second key, etc.).
I would also save all object-related documents in the Object File (or the Donor File if they are confidential). They do not need catalogued if they are saved in the corresponding Object or Donor Files. I view the documents you mentioned as relevant to the object's history and not necessarily useful as archival records. However, this does depend on how your Archives are set up. Ours functions as an institutional history, so it would not be helpful to have award certificates that pre-date the object's history at the museum.
------------------------------
Rebekah Furey
Collections Manager
Conner Prairie Museum
Fishers IN
------------------------------