6d625064_e_of_a_series___interest_co_nz__Potential_information
[Source] Accreditation or certification bodies [Potential information] 
If the business is subject to any other form of audit, certification or accreditation of their activities those bodies may have records that could be used.
Reconstructing records lost in a disaster is a big task. Here are some helpful suggestions on how to go about it. This is part three of a series | interest.co.nz
Potential information