I feel like, their father has allowed this estrangement to continue in a way that might make them feel he didn't care about them - and at this point they probably wouldn't accept an effort from him since he has been so distant (he did not originate the estrangement, but also didn't put forth the persistent effort I would expect from a parent to repair that - kids can push you away but you as the parent should keep trying). But if they had regrets after his death, I thought perhaps something from him expressing his care might be helpful.
I certainly want him to write down his family stories so the girls can know their history - since they were teens/college when the rift happened, they probably had not absorbed some of the information about his parents/grandparents/family history that they might want to know in the future. And I can certainly put together a youtube memorial reel and send them a link so that if they choose, they can see some pictures of their dad's last years. They might not be interested but if they felt any guilt it might comfort them to see he was well cared for.
I also have genetic information that they might want to have, since we have sequenced CMMs genome. And I can summarize his medical history should they ever need that info.
There won't be any money for there to be a fight over, and I will have him put any mementos in a box that I could give them if they wanted them.
For those wondering, the estrangement came about when the marriage blew up - to hear him tell it, alcoholic wife falsely called the cops on him and he had to be the one to leave, after he had been trying to keep it together for the remaining teen at home. I don't have any reason to doubt his story, but who knows what the girls believe. And unfortunately, 6 mos after they split, he suffered a serious knee injury at work that sidelined him for a year, and resulted in everybody pretty much losing the nice lifestyle his income had provided (wife didn't work and never really had done much work). He did return to work after a year but never regained the good jobs like he had before (age discrimination, changes in the business environment, etc.) I'm sure the girls resent the change from indulgent suburban daddy to absent broke father. They might also resent him leaving them to deal with their alcoholic mom, I don't know. I suspect he was also rather difficult as a dad when they were teens, as he was strict about who they could date etc. He can be difficult with his OCPD.
It's a shame because when they were younger he seemed to have a close relationship with them, if photos are to be believed - they golfed together, he took them to all their sports games etc., he has many childhood mementos from the girls. That's why I would like to have something to give them when he dies. Anything else isn't really my business.