20a – Foreign Activities

I am coming from the humanitarian NGO sector and have been overseas the past 20 years. In various senior roles over the years I have been a signatory to my NGO’s in country bank accounts for paying staff, vendors, etc. I have always filed an FBAR but can seem to only access the info going back a few years.
1)I am assuming I need to declare all these accounts? Also, should I just included as much information as I know and explain why I don’t have more information?

Also, in at least one, maybe two countries I have also opened a local bank account for ease of being reiumbursed for expenses while on mission. I cannot even remember the names of these banks. How would I list this?

Thank you!