One long ago gave up any hope that Hollywood would give up any “hit” intellectual property without wringing the last drops of value out of it. But the news that there will be a third “Downton Abbey” movie, with Paul Giamatti reprising a character from the series and that Joely Richardson and Alessandro Nivola will join the cast for it, gives me an excuse to renew my plea that this worldwide phenomenon, running on setnimental fumes for its most recent big screen treatment, be given a graceful, apt and historically-defensible send-off.

“Gosford Park” screenwriter and series creator Julian Fellowes has been reluctant to take the Great House and its era towards a natural coda, which might be the lone gripe I have with this popular, populous and period-perfect highbrow soap opera.

It was never going to be “Brideshead Revisited,” because Fellowes, a terrific screenwriter, is no Evelyn Waugh. But “Brideshead” points the way for how to wrap this saga up with a fond farewell to the age of legions of lower-class Britons employed “in service” in a vast, unmanageable mansion whose inheritance, National Trust listing and tax breaks still would rarely be enough to keep it practically liveable.

“Brideshead Revisited,” based on the 1945 Waugh novel, has been filmed a few times, most famously as a 1981 TV series that became the “Downton” of its day. That story, told in flashback, used the World War II service that great house — Brideshead — as a training grounds/billeting for the British military as its framing device.

One could see the house as it once was and what it would become, nothing any one family facing progressive taxation could afford and keep up in the manner of such manors of the past, a mansion symbolic of Britain’s class-divided past and somewhat more equitable future.

Something like that was the subtext of the early run of the “Downton Abbey” TV series — World War I intruding on the stately pile and its generations of inhabitants, a property saved by the heir’s timely marriage to American money now full of people “doing our bit” for the Empire and the war effort.

World War II, its grim tests and a culture bracing for “the change” that would sweep over the British aristocracy and their estates in post-war Britain would be a great way to wrap this story up, giving the locale and its inhabitants purpose and the viewer a bit of “We’ll meet again” and “Keep Calm and Carry On” nostalgia.

Literally anything else — another story set in the ’30s, immune to the worldwide depression outside their grounds — would just be more of the same, cinematic running-in-place. And I would hope Fellowes wouldn’t want that, no matter how much Focus Features might.