The cowardly crooks who pistol-whipped a 79-year-old woman during a caught-on-video jewelry heist in Queens last week made off with $1.1 million in merchandise — more than twice what was initially reported, police said Tuesday.

Cops said the four thieves — including one dressed like an Amazon deliveryman — remain on the loose following the harrowing Feb. 22 robbery that left the victim at Diamond Collect in Flushing battered with a blood clot to her head.

“It was pretty brutal what they did to that [79]-year-old female,” NYPD Chief of Detectives James Essig said at a press briefing Tuesday.

“She gets knocked on the floor, pistol-whipped, both kicked her, they drag her to the back trying to get her to open the safe with a gun. It’s pretty harrowing.

“She says they don’t say anything to her,” Essig said. “She, heroically, closes the safe and takes out the key. And that’s when he has the gun on her asking her to open up the case.”

Yuchi Lin, the mother of shop owner Eva Chen, was manning the counter at the store around 2:30 p.m. while her daughter was grabbing lunch, police said.

That’s when the faux Amazon deliveryman placed a package outside the locked door, hid around the corner — and pounced when Lin opened the door to grab the box.

Two of the crook stormed into the store wielding a gun and a hammer while the other two waited outside as lookouts, Essig said.

The pair in the shop attacked Lin and smashed the display cases, making off with rings, watches, pendants and chains, initially believed to be valued at $500,000, though Essig said Tuesday the stolen merchandise was actually worth double that amount.

The thieves fled in a black Mercedes-Benz.

Police have released surveillance camera images of the suspects in the hopes of identifying them.

“We’ve had 11 jewelry store robberies this year so far,” Essig said. “None fit this particular pattern.”

NYPD Chief of Department Jeffrey Maddrey said the department is urging Big Apple businesses to be more “proactive” to avoid getting hit by crooks and is offering free surveys for merchants to review their vulnerability.

He said face masks mandated during the pandemic — and still worn by some New Yorkers — can offer would-be thieves a shield as they work their way into a store.

“We’re asking the businesses to be proactive with this,” Maddrey said. “We’re asking businesses to make this a condition of entry, that people when they come in, they show their face. They should identify themselves.

“And if they feel like they want to put their mask back on after they identify themselves for their safety, by all means, they should do so,” the chief said.