Then I would say it doesn't matter what you send. Assume that this is just the olive branch. View it as an olive branch. Don't put anything it that doesn't need to go in it. If he responds positively, great. If he doesn't, at least you sent out that olive branch.

You can't go back and undo everything that was done. Whatever negative emotions he has towards you, you earned that through months years. One letter is not going to make a difference. You have to know that going in.

That's how I would view it, but I'm a f'd up person.