I grew up with a close family on my fathers side, and love them all. But when things went sour, there were a lot of harsh things said and a lot of hard feelings. My father past first and when he left we were on bad terms. It was very difficult for me to overcome this and sometimes I wish that weren't the case, but it was. In the big scheme of things, I have no regrets for my feelings, because they are feelings I learned later in life I am entitled to, just as anyone else. Do I wish it weren't so? Sure, but there are just things that are outside my control. So, I stuck around to be close to my Grandmother, whom I adored! I bought my condo close by so I could be close to her and when she passed, I never really looked back. Although I grew up here, my one Uncle I had no problems with moved back to his home state and if I were to see him, it would be on a visit to my Mom's side of the family and one of my Uncles (Mom's bros) would get ahold of him and bring him to visit me. He has recently passed and I didn't go tot he funeral, as an Aunt whom I don't get along with over harsh words was there and I figured she had the first rights to be there.
So, with that said, if YOU FEEL up to it, maybe you could stop by for a short time. However, this is about your Uncle and paying respect to him and his family, not just your Dad, his brother. Possibly not the time for your Dad to rehash and free himself of the guilt he has on his back.
I hope this helps.