Prospective recipients may have balked at items that so viscerally evoke the street scenes around the trade center after the 2001 attack, even though the objects themselves are not directly connected with the 2,753 people who were killed that day.

As the distribution program nears an end, two museum directors marveled that it even began.

“The Port Authority of New York and New Jersey is not a museum,” said Mark Schaming, the director of the state museum. “They did heroic work. There was no handbook. There was an instinct to collect things for a museum that didn’t exist. It was curatorial triage. The site was still burning, yet they were going in there and pulling things out.”

Image The plaza signage from Five World Trade Center, a nine-story building that stood at Vesey and Church Streets. Credit... Johnny Milano for The New York Times

The state museum acquired about 150 objects from the hangar, including the Port Authority Police Department vehicle used by Officer David Lim and his explosive-detecting Labrador retriever, Sirius.

Alice M. Greenwald, the director of the memorial museum, credited Robert I. Davidson, then the chief architect of the authority, with reaching out to the architect Bartholomew Voorsanger soon after the attack to say, “We’ve got to save some of this stuff.”

Mr. Voorsanger assigned his colleague Mark Wagner to comb the wreckage and decide — on the spot — what pieces warranted saving for posterity. Mr. Wagner later joined the architectural firm Davis Brody Bond, which designed the memorial museum.