Kind of looks like it's been somewhat picked, I agree with the comics sentiment - they are either stored elsewhere or were already sold before he died. Maybe he personally went through the collection and sold off what he knew was worth anything, ask the widow? :shrug:
And those marvel stamp books? Why would he have 3 mint copies and no comics? The money has to be stored elsewhere, if there's a storage locker that he kept to himself it would be a nightmare if the fees don't get paid...
I would scour the house before contacting anyone, I did a website for a local coin/collectible dealer and have heard many stories of fake walls under stairways, sealed off crawl spaces, and a coin horde that was found under a house foundation.
This is decades of collectibles, he has OSPGs, kept boxes. He knew what he had.