These cabinets are so rare, I have to wonder how it wound up on the curb. I'd imagine there's no way it's a happy story, unfortunately. Someone apparently felt that was worthless.
There is a significant probability that mom was tired of hearing "I'm gonna move it out of the garage, soon" and just said to hell with it.
I'm gonna guess "belonged to former husband". Dead or divorced, who knows.
That might be due to movie accounting. There are times the producers of the movie have an incentive to make sure a movie has little or no profit, even if it does okay at the box office. For example when someone other than the producers will contractually get a percentage of the net proceeds of the movie.
It's not a great example (I have no idea about his specific motivations), but one example of how to tweak those knobs is when Kubrick's films had to use special equipment that was literally only available from a single company. A company that Kubrick happened to own, and could decide how much it charged the production. You can see how anyone involved in the production who had a piece of the film's net would have the size of their piece impacted by however many millions went to Kubrick's company.
(there's a play in which greedy producers joke about how "there is no net!" but I can't for the life of me remember much about it beyond that joke)
I calculated it out once, and if he'd taken the deal they were offering, Connery would have - based on what the movie grossed - made a decent slice of a billion dollars.
He really needed someone savvy to guide him, which he never got. At least he made The Rock .
Owning a Medieval Madness table has become one of my "boy, if I ever won the lottery" fantasies, and will likely remain that way.