I am also facing updating old accession records. I don’t think anyone has pointed out the problem with the older numbers not showing the century i.e. 1977-. Our collection is small enough that as we type up handwritten forms we can add the “19” and go add it to the item. But I will still add a note to the collection paperwork that for any record with the two digits only, like77,77=1977. Any 21st Century accessions will have the “20–” number. We don’t have PastPerfect, yet, but it is good to know they have an “old number” area.