I just keep thinking of the part of Michele's book that talks about reaching out in different mediums, and how sometimes people respond to different things.
I don't think that this is one of those scenarios. If you've said the things before that let him know you want the marriage to work, reading it won't make any difference, it will just be more pursuit. I'd vote a big NO to the letter.
You cannot be lonely if you like the person you're alone with. Dr. Wayne Dyer