I personally have a go-box that contains the most important papers in case we have to make a quick exit due to fire or weather.
I think you are on the right track. His sister says she sent him papers about the life insurance policy and I have not found those either. He had a huge filing cabinet and it was pretty much full. I have been through everything. I think the most important papers are still missing.
I felt the discovery of the safety deposit key in the top of the tool chest was good. But he had not been in that box since June 6, 2008. I did get the high school diploma but he never reguarded that as valuable.
I never saw or heard of him having a safe.
Thanks for your response.