“If they don’t make it, it won’t be for lack of trying,” said Mr. Connor’s brother Harry, who holds down a regular spot at the end of the bar every weekend.

Chris Santangelo, 43, another childhood friend and a bartender at Donovan’s since 1995, is working harder than ever these days. He is managing the place, squeezing in acting gigs when he gets them. Theresa Ashton, a veteran waitress who quit seven years ago, has returned. (She lost a lot of weight, and the regulars can’t get over how great she looks: “Have you seen Theresa?”) Craig Geraghty is bartending again, and advising on the menu. He runs a seafood-catering company and taught the cooks his recipe for crab cakes. Mr. Jacobson’s older brother Gary, a retired firefighter, is back behind the bar a couple of nights a week.

Mr. Jacobson, a graphic designer by day, is talking about giving the faux-Tudor, half-timbered exterior a new paint job. But inside, the Irish kitsch mementos and the plaques celebrating softball teams from the ’70s and local firefighters who died on 9/11 have been left alone.

So far, the most notable change has been the computerized cash register system that Mr. Connor, who works in information technology, installed. The ability to pay with a credit card is a popular novelty, even if some of the older waitresses are struggling to get the hang of the system and persist in calling out drink orders to the bartenders, rather than waiting for a printout to pop up behind the bar.

But for the most part, the new owners’ plan for the future seems to be to take a couple steps into the past. It is safe to say that the place will not be turning into an artisanal cocktail joint any time soon. Donovan’s is going to be, more or less, Donovan’s.

“We’re just trying to bring the charm back,” said Mr. Jacobson.

Their aspirations are not all that different, actually, from Joe Donovan’s, back at the beginning. When he and his father bought the place, in 1966, it was a rough spot called the Clover Leaf — “a neighborhood gin mill that had no business,” Mr. Donovan, 79, said.