Satisfactory completion of a project

Page 11, #6. says to provide documentation evidencing the satisfactory completion of a project, namely,certificates of occupancy. We completed 20 homes in the USDA mutual self-help program between 2005 and 2007. We have 7 CO's from our last group but do not have CO's available for the first 13 homes. Is there another document that would be accepted, or a letter from USDA verfying completion of the project?