Codicological descriptions of late 16th-century Lithuanian Metrica bookcopies reveal the history of these manuscripts’ production, the organisation of the rewriting work and their later archival history right up to the present day – the 21st century. This article discusses the established codicological (paleographic) methods that are used in Lithuanian Metrica historiography to help distinguish the text from no-longer-extant original books from the additions made by subsequent rewriters when adapting them to the particular needs of the day and enabling easier searching for information in the books of the Lithuanian Metrica. For this purpose, I have used the studies by Egidijus Banionis (1948–1993) dedicated to the genesis of the early (pre-1506) original Lithuanian Metrica books. In the context of this research, an assessment was made of Oleg Chroruzhenko’s latest attempt from 2008 to use the codicological characteristics of these book-copies to answer questions about the physical nature of the original books and their structure.