Based on those things — a wedding photo, a receipt for war bonds and an old Social Security card — Zakrzewski's son, Michael, spent the past year piecing together his father's life.
"Nobody in our family knew anything about his military service," said Michael Zakrzewski, 61, of Harwich. His father left when he was in the seventh grade and died in 1987. "We didn't know where he'd served ... where he was buried."
But on Tuesday, during a small ceremony at the Hyannis headquarters of the Nam Vets Association of the Cape and Islands, Zakrzewski received four medals for his father's service in the Pacific theater during World War II, filling in some of the holes.
A Purple Heart also was presented to Regina Burkinshaw of South Yarmouth, the sister of Army Pvt. Joseph Byrne, who was killed in action in 1944.
For both families, the tiny pieces of metal — given by U.S. Rep. William Keating, D-Mass., and retired Air Force Gen. Jimmy Dishner — were huge testaments to their family legacies.
"It means so much to him," Michael Zakrzewski's wife, Nancy, said before the ceremony. "The day he found out, he called me at work and said it was like getting an early Christmas gift."
When Burkinshaw, 92, arrived Tuesday to receive her brother's Purple Heart, she expected a quiet office and a quick handoff, not a ceremony with dozens of people, she said.
"It's unbelievable. It's so many people," she said, cradling the small medal. For the ceremony, she tucked into her purse a picture of her brother's grave, marked with a white cross like the thousands of others around it, at the Lorraine American Cemetery and Memorial in St. Avold, France.
It had been decades since the family had seen Byrne's medal.
In the spring of 1945, Burkinshaw opened the door to a message that she'd lost her best friend and closest brother.
"I was home alone and I received the Western Union," she said. It included word of Byrne's death on Nov. 24, 1944, and a tiny box with the Purple Heart in it.
He had left Camp Edwards just three months earlier.
Through the decades, the family lost track of the medal, and had only a dusty, framed citation to remember it by.
"We didn't have the medal or anything else anymore," Peter Burkinshaw of South Yarmouth, Regina's son, said.
So he approached Keating's office to replace the medal, waiting a year to receive it, he said.
"But I'm hardheaded. I don't take no for an answer. And now we have it back," he said.
Zakrzewski, too, faced a yearlong wait for his father's medals after he approached Keating.
The search for his father's military history was hampered, Zakrzewski said, by the complicated surname, which was misspelled both on the war bonds receipt and his father's gravestone at Calverton National Cemetery on Long Island, N.Y.
A friend of his late mother's in the Social Security Administration clandestinely provided information on where his father was buried, and the Army was finally able to match the misspelled name and birthdate to find William Zakrzewski's honors, which included three bronze service stars.
"It just fills in a lot of blanks. All I remember of him is bits and pieces," Michael Zakrzewski, a Navy veteran, said.
The process to posthumously award military medals is a fairly complicated one, officials said.
If it's been more than 10 years since the award was written up — but not necessarily given to the veteran — a congressman must apply for the honor, Merrill Blum, executive director of Nam Vets, said.
In some cases, there are issues with documentation — for example, Zakrzewski's name being misspelled, or a record being one of thousands destroyed in a 1973 fire at the National Personnel Records Center in St. Louis, Mo., Lauren Amendolara, a spokeswoman for Keating, said in an email.
Keating's office has worked with less than a dozen families to get medals and currently has another dozen applications pending, she said.
The process to get medals averages six to nine months, Amendolara said.
Still, veterans advocates think it's important to remember veterans, including World War II veterans for whom waiting a few years could be too late.
"If we find out that an award was given (and not received), or not given, we need to take the time to reflect on that," Dishner said during Tuesday's ceremony. "There are fewer and fewer of them now."