I came across a personal notebook of Joe's. Since he was such a private person in life it is extraordinary to get an insight like this into his feelings for Marilyn. This was written after their divorce but it shows that Joe still hoped to make a go of it. Here he tries to remind himself what he needs to do to win her back.
"No jealousy. Remember this is not your wife. She is a fine girl and remember how unhappy you made her. Happiness is what you strive for- for HER. Don't talk about her business or her friends. Be friendly towards her friends. Don't forget how lonesome and unhappy you are - especially without her."
This really is extraordinary stuff. I had a different perspective on Joe after seeing all the personal items he had kept. The fact that he still displayed photos of Marilyn in his home at the time of his death was incredible to learn.