Netcell checked in with Vickers regularly during the past decade, but when a family illness became all-consuming last year, her phone conversations with Vickers became less frequent. She last spoke to her in June.
"She thought people were stalking her," Netcell said.
Tom Weaver, 53, a horror film historian who lives in Sleepy Hollow, N.Y., also said Vickers exhibited signs of paranoia.
As a freelance writer fascinated with cult horror films, he had sought her out decades ago, "because nobody in the '80s knew what had happened to her."
At the time, he tracked down her address, and when he arrived at her home, he was in disbelief. He thought to himself, "Nobody could live here, this was such a rat hole."
Nobody answered the door, so he left the broken windows and weeds, and later tried to contact her by writing a letter. She agreed to meet him, but only outside of her home, which was the same request she made of nearly everyone else in her life.
When they finally met up, he encountered a "Funny, sweet, lovable lady." After that, they stayed in contact, mostly via phone.
"She started calling me at home, 'How are you darling, and that kind of stuff,'" Weaver said. "She was fun to talk to -- she was a talker. You didn't get a word in edgewise -- she could go on and on, and she did."
He most recently interviewed her for an audio commentary on the 2007 Warner Brothers DVD release of "Attack of the 50 Foot Woman."
Weaver speculated, "Her downfall was paranoia and drinking -- she chased away all her best friends."
Don Prell, 81, a jazz musician living in San Francisco who played in the city symphony for decades, was married to Vickers briefly in the 1950s.
"To me it was such a big thing to meet a lady whose father knew Charlie Parker," he said.
They were rarely in contact after the divorce, their last phone call was about two years ago, he says, a conversation in which Vickers requested newspaper clippings about their marriage.
Prell remembers the younger Vickers as being ambitious: always going on auditions, she wasn't the type to "sit around waiting to have a baby."
"She was going to be an actress no matter what," Prell said.
Neighbors Reflect On Vickers Tragedy
So far two people have come forward claiming to be Vickers' family members: a possible brother and cousin, according to the L.A. coroner's office. But Vickers' friends and ex-husband Prell say she always told them she was an only child.
"I don't think she has anybody and that's probably the saddest thing," Prell said.
Neighbors who lived near Vickers on the narrow, winding street in Benedict Canyon knew little about her, describing her as a private woman who isolated herself from the community.
Terri Cheney, a bestselling author and attorney who has lived on Westwanda Drive for nearly seven years, resides across the street from Vickers, about two houses down.
"I was just shocked. I didn't realize that no one had seen her, that no one knew about her. I didn't know she was an actress, for example," Cheney said. "Just that she seemed extremely nice."
After hearing the news, Cheney called her mother.
"She lives alone so I immediately went home and called," said Cheney, 51, who also lives alone.
One neighbor said his gardener had seen Vickers watering plants on her porch in December or January, but it's unclear if anyone came across her after that.
Ever since neighbor Savage made the discovery last week, the L.A. coroner's office has been working to confirm the body's identity, a process that could take as long as a month if it's forced to rely on DNA evidence.
Autopsy results are still incomplete. The body was so badly decomposed, it still isn't clear if the body is male or female. If officials can find dental records or Vickers' doctor they could identify the body in a few days, Winter said.
"We're pretty confident we're going to be able to identify her," Winter said.