"We Believe in Yesterday" is the third and final book in the "We Remember it Well" series which began in 1995, and forms part two of the preceding volume "I Could Have Told You".
The book was compiled through 275 tapes from interviews, and the memories included were whittled down from more then 2,500,000 words by Professor Barry A Thomas.
Terry Farrell, who provided 'technical support', helped compile and organise the information, and hopes the books will provide a definitive history of the town.
"In school, when they said the essays had to be 500-600 words, mine would be 27 pages long!" he said.
"That's why we needed someone professional like Barry Thomas to condense it down."
Terry, who has been assisting the Penarth Past group for 22 years, said that each interview covered a wide range of topics.
"I have four sheets of paper that details who did the recording, with whom, on what date and what topic," he said.
"You start interviewing someone and then you go off on a different track.
"For every single person we interviewed, we would have a 10 minute interview and 30 minutes where they changed the subject and talked about something different that is absolutely fascinating!"
Terry said that a lot of Penarth Town Council's archives were lost years ago during flooding.
"That's why these are so vital," he added.
"Everybody has one tale that they think would interest someone. ThereÕs enough material there for another group to do another book."
The last two remaining members of Penarth Past are Treasurer Margaret Twynham and Sheila Martin, whose late husband Harry was previously Treasurer.
The original idea for the series came from Joan Collins, who died in 2008, who completed many of the interviews herself.
"We Believe in Yesterday" covers a wide range of topics, including the development of Penarth Docks, the Barrage, local schools, businesses and churches, as well as featuring old photographs of the local area.
Terry, 69, said the book would also act as a tribute to Penarth Past members who have died over the years, with pictures of the 22 members included in the last few pages of the book.
"It's a bit of a tribute to the people that helped compile it," he said.
"We Believe in Yesterday" is available from A B Snell and Son on Stanwell Road.