Every good thought for you and your dad. It has been just a few years since my dad left us, and it is still very fresh in my mind. It was a time of sharing for the family. My mother died many years ago and dad outlived two more wives after her.   We didn't want him to be alone so family was with him until the end, including a granddaughter who is a nurse and another who is a nursing assistant as well as a hospice nurse who made frequent visits. They were able to take care of his physical needs very well which helped all of us feel better, but there is no way around the truth--that he is gone and we miss him so.
How wonderful that you have recordings he made. I still think of Dad's wonderful whistling and wish we had recorded some of that.
Your love for him and his for you is so evident in the posts and it blesses your readers on Mudcat as it must bless your father and his wife.
I will especially remember him as he has the surgery. I hope it does give him the expected relief.