Condolences for you and your Mother on your Dad's passing. It can be hard to handle these things, but it is what we do for our parents.
That rifle is a fine piece of German engineering and craftsmanship. I have a soft spot for Krieghoff, as it was the first type of double rifle I fired, courtesy of a fine gentleman at the range in South Carolina.
Going on his 12th Safari, and the rifle had its share of experience marks. Elephant, Hippo, Cape Buffalo, Lion all fell to that rifle. I was hooked and it was accurate.
Maybe you are already aware, but the Krieghoff design, with the "thumb cocker", looks like an oversized safety, but is actually a thumb cocking device, that cocks the firing pins, when pushed forward, rather than just retracting a safety on already cocked firing pins.
Thus, the rifle is carried with rounds in the chamber, but with uncocked firing pins, until this is pushed forward. for shooting. The firing pins do not rest on the primers. Very safe, as much as a firearm can be.
My SC acquaintance bought this because, when hunting with the same PH in Tanzania for years, one of his trackers was wounded when another client's old school double accidentally discharged, after dropping his rifle, with the safety off. Of course, we know the best safety is between our ears, aware of the muzzle direction, but sh$t happens.
The tracker survived but was crippled. My acquaintance could buy any rifles he wanted, but bought the Krieghoff, a pair in .500/416 and .30/06. He used nothing else.
Your Father's rifle is a fine example, and the wood is really nice. Somebody will get a fine rifle system.