At Mia, we create TMS object records for all potential acquisitions as Object Status = "Acquisition Candidate" and assigned a specially formatted Loan Object Number (e.g. L2015.16.1). Our registrar just created a Physical Parent / Intellectual Child record set using this approach. The item(s) in question were then acquired, their Object Numbers edited to normal Object Numbers and the Object Status in the Physical Parent changed to 'Accessioned'.