It sounds like you're in a much better place than you had been. Do you think you could reach out to the brother whose wife you spoke with? Think he's ready? Not to talk about AM, just to talk. About everything or nothing. Something to get a positive association going between the two of you again?
My sister and I may not always agree on everything, but I'm still glad I have that relationship - even amongst ACoAs, the stories are so different that the only person who can truly and deeply understand when I say "it's a dad thing" is my sister. That's worth more than any amount of money.