You’ll have to consult with a canon lawyer about that. In the meantime though, I recommend consulting with a civil lawyer about petitioning the court to produce another official copy of the original divorce decree. Legal documents that govern the structure of society cannot simply be “lost” and allowed to “disappear.” For example, when my own grandparents, both born in 1909, were trying to obtain work in the 1950s, they did not have copies of their birth certificates and the counties where they were born no longer had the birth certificates on file either. So they went through a legal process to get new birth certificates issued. Surely there is a similar process available for getting a court to provide a new official copy of a previously-granted divorce.