The paint, trim, stained dark floors and pot lighting are all upgrades to a house of that age IMO. Not sure when all this was done but probably while WM was alive. He was supposedly a humble and frugal man though (drove an old pick up instead of a fancy car) so the old school furniture is likely stuff that he considered still in good shape and chose to keep after the update to the house. The mess? That's probably all DM. And it's not like CN was going to help him keep things tidy.
I shudder at the thought that he moved himself into his father's master bedroom after his death, especially considering he allegedly murdered him. I'm sure he had a room of his own in the house prior to that. Even if WM had actually committed suicide, I can't see his son moving himself into his bedroom within months of his death. :notgood:
MOO
ETA: And if the upgrades to the house were done after WM's death, then I'd say MB had a hand in getting it ready to be sold.