Although we have never met, I, too, am sorry for your loss!
My wife & I go over what I have fairly often, but we have never formed a "Game Plan" about how she might want to dispose of things in the event that I pass before her. Luckily, I have 3 brothers who still collect who will be happy to help...I hope!
Regarding your Pa's coins - and this is NOT intended to be a solicitation for business...
Being retired from my profession as an Environmental Geologist, I now help families & friends dispose of collections, partial estates, and "stuff" on commission. Sometimes its done via eBay or here and other times via contacts that I have made AND TRUST over the years It is NOT always an easy thing to do as there are SO MANY times when sentiment is tied into an item. THOSE items should remain with the family.
That being said, I am sure that there are people who do what I do in your area, too. Find one or two, sit down and meet/interview them - you WILL find one of us with sincerity, dignity, & integrity who will help you move your Dad's collection or at least assist you with what is good and what is not so good.
I find that it is STILL fairly easy to judge people by meeting with them face-to-face.
I would be more than happy to talk with you, if interested. Please feel free to PM me.