Seasoned real estate brokers Jessica Fields and Brad Bateman thought they had seen every type of listing imaginable — until they were tasked with the sale of 1019 Bushwick Avenue.

Stepping into the Brooklyn mansion, which was built in 1900 and just hit the market for $2.7 million, was like slipping through a portal back in time, the agents told The Post.

A dazzling array of relics filled the more than 4,000-square-foot home’s lush interior — from ancient television sets and classical busts to century-old stoves and dolls.

The home, the agents said, looked less like a residence than a staging area for a Bushwick edition of PBS’s “Antique Roadshow.”

“The house feels like it’s out of a history book,” said Fields, the listing agent with Compass. “It’s been largely untouched since it was built in 1900.”

From original pearly pink bathroom sinks to hand-painted wall murals to old saltwater taffy boxes, the seven-bedroom, five-bath space had successfully repelled a century’s worth of design trends.

Fields said much of that consistency stemmed from the fact that home has been kept in the same family since 1937.

A recent tour revealed treasures in every direction. A rare, first-edition copy of Betty Smith’s “A Tree Grows in Brooklyn” from 1943 hid in a stack of old children’s books. A row of valuable vintage dolls — including characters like Pinocchio and Snow White — stared out from atop a high shelf in another room. A housecleaning schedule — nearly a century old — remained affixed to the inside a closet door. Tuesdays, it decreed, were reserved for a thorough cleaning of the “music room, sun parlor, and hall.”

A rear portion of the home had once been used as a doctor’s office, the agents said. Their first exploration revealed vintage desks, examination tables and a pile of dusty patient logs.

In researching the address, Fields and Bateman learned that the mansion had been designed by Ulrich Huberty, the son of a successful German-American businessman named Peter Huberty.

The scion was considered a Gilded Age wunderkind, having taken part in the design of many prominent borough landmarks — including the Prospect Park boathouse and Williamsburgh Savings Bank.

Hubert created the Bushwick Avenue home for his parents and it was completed in 1900. But the young architectural star — and devotee of the City Beautiful Movement — would die suddenly 10 years later at just 33.

Fields and Bateman said they hope that the ultimate buyer will retain the resilient spirit of the home, which was deemed a landmark by the city in 2017.

The current owners plan to organize and ultimately sell off the antiques and ephemera — most of which was gathered and stored out of view for the sale process.