LOS ANGELES — There were many reasons to rave about HBO’s recent biopic “You Don’t Know Jack,” which aired in April. Who would have thought the story of Jack Kevorkian, the euthanasia activist turned controversy celebrity, would have made for such a rich and moving story? Director Barry Levinson, for one, and star Al Pacino for another. Pacino was the major recipient of the general critical praise – the star wore understatement like one of Kevorkian’s cardigans, taking a figure who had become a caricature and making him heartbreakingly, mind-bendingly real.

And then there was Brenda Vaccaro.

Brenda Vaccaro! A blast from the past, with her throaty dry humor and salty frank self miraculously intact, meeting Pacino word for word, look for look as Kevorkian’s sister and partner in crime, Margo Janus.

Brenda Vaccaro, from movies like “Midnight Cowboy” and “Once Is Not Enough,” from Broadway hits like “Cactus Flower” and “Jake’s Women” and, of course, those fabulous Playtex ads. Her Margo humanized Jack just by standing by him, helped him channel a doctor’s frustration and fury at how patients are either kept alive and suffering too long or allowed to die of starvation and kept him right-sized and focused on a solution.

With Pacino and co-star John Goodman, Vaccaro injected the humor, and the pathos, that lifted the story out of the magazine archives and made it human.

“It’s rum raisin,” Margo says when her brother comments on her new wig. “I think it makes me look, um, a little more fetching.”

Brenda Vaccaro. Where on Earth has she been all these years?

In Encino, Calif., it turns out, trying to keep her career from shuddering to a complete halt.

“Oh, I wanted to work, Toots,” she says, over lunch on Ventura Boulevard. “But I couldn’t get roles. Hell, I couldn’t get representation. These agents, they would say, ‘Let’s face it, it’s the age’ or ‘You don’t make enough money,’ or they already had old cows on their plate and there are too many old cows out there already.”

She laughs and heads turn, because that laugh is a work of art, rich and raspy, full of outrage and surrender, of years pitching it to the lady in the upper balcony and the suit behind the desk. Time has not worn this woman smooth, though she looks much younger than her 70 years, and not in that overtly surgical way. Instead, it has washed her rough around the edges, not splintery but carefully distressed, like a marvelous kitchen table on which use has left its mark and made the piece more valuable for it.

“Barry Levinson, he saved me,” she says, turning serious. “He gave me back my vocation. It had been taken from me.”

Indeed, after three years of not being able to land even a guest spot on a police procedural, Vaccaro and her husband, Guy Hector, were about to call it a day, to quit L.A. altogether and move to Hector’s native France. Out of the blue, she got a call from casting director Ellen Chenoweth asking if she’d like to read for the part of Margo. Vaccaro thought it was a joke, but off she went to HBO. Having watched her own beloved mother die all too slowly, she knew precisely what Margo and Jack were fighting for. And what she herself was fighting for as well.

“I was so excited just to get up and act again,” she says. “I had such a good time, but when I got back in the car I said to Guy, ‘Honey, forget about it. It’s Al Pacino.”‘

Vaccaro had known Pacino in the old days, the theater days, when at one point, she says, they shared a manager. “And he came to see me backstage when I was doing ‘Jake’s Women’ with Alan Alda, and I said, ‘Al, we have to work together,’ and he said, ‘We will.’ Of course, I didn’t know it would be, what, 12 years.”

Levinson liked the tape, Pacino liked Vaccaro and, suddenly, she was back in business, working nonstop and having the time of her life.

“I missed it so much. I went to work like an 11-year-old on a bicycle,” she says. “And Al is such an actor, what an actor, never did we take a day off. Conversations, rehearsals, rewriting the script, going back to the original script, more conversation, more rehearsals.”

Vaccaro has never given up. She’s done bit parts, commercials, master classes – she’s taught acting at the Malibu Senior Center and was overwhelmed at the dedication and talent she saw. And now, in the wake of “You Don’t Know Jack,” Vaccaro and her husband have decided to see what happens next, though, nothing much has so far. Though she got a lot of praise, and more than a few e-mails from people she hadn’t heard from in years, Vaccaro isn’t juggling offers.

“God makes you rest with the excellence,” she says, with another rucked-up laugh.

Let’s just hope he doesn’t let her rest too long.

Brenda Vaccaro and director Barry Levinson arrive at the Monte Carlo TV Festival 2010 on June 6 in Monaco.