Born in Texas
Mr. Glawson is most easily dated by his appearance in The Genesis Children. Released in August 1972, the movie must have been filmed at least a year earlier, presumably during the summer of 1971. In that movie Peter is an adolescent, while in the short film Swim Party, filmed before the fall of Lyric in 1973, he is clearly a young man.
An "incomplete and unofficial" biography of Peter was posted on Usenet in January 1999 by Boyhowdy , who that same month posted a series of published photos of Peter, along with commentary which survives on Google Groups. He states that Mr. Glawson was "born in the mid-1950s (probably 1955 or 56)." That would make him 15 or 16 in The Genesis Children, and 17 or 18 in the last Lyric films.
Boyhowdy goes on to say that Peter "spent his early years in Texas with his older brother, Rick and younger half-brother, Maxey". Billy Byars, Jr., who founded Lyric, was raised in Tyler, Texas, and a Lyric film shot in Texas, Sandy Hill, features a younger Peter. Another Lyric film, Summer Freedom, shot on Padre Island National Seashore in Texas, may also include Peter. The same Usenet post also says that, "the earliest published photos of Peter that we know of are the ones of him and Maxey and Billy Marshall and the other boys on the Gulf Coast of Texas (playing along the beach). Peter is 12 in these photos."
Peter appears in The Genesis Childen wearing a Tyler YMCA T-shirt.
Peter in California
Boyhowdy’s "incomplete and unofficial" biography says that, "When Peter was around 12 … he and Maxey moved from Texas to California to live with their Uncle Terry." Terry’s status as "Uncle" is discussed elsewhere. Other sources describe Maxey as the actor Max Adams of The Genesis Children. One of those involved in the scandal, a Lyric producer, said in a 1975 interview that police coerced an accusation from the younger brother of a boy who lived with him. The younger brother, 13 at the time, would have been born in 1960. This scarcely identifies Maxey and Peter, for having a brother is only somewhat rarer than having a mother. The producer also says that the younger boy came on weekends to stay with his brother, and mentions an alcoholic father, all of which would suggest that his houseguest’s family was close by, and not in Texas.
The producer also denied that the boy was his lover, but acknowledged that many – including the younger brother – believed that to be the case at the time. He also said that at the time of the interview, the older boy was in the Army.
An anonymous online source who claims to have known Peter says:
"I would say that he was totally straight and not a nudist but a 'financed boy' who was resident with an older person. He liked being looked at but I would doubt that he was that keen on looking. He was brought into the big city from the country and I would say that it was his practical nature rather than anything else that kept him there." 
Among the Lyric models
Peter appears in Lyric’s magazines and films over what is clearly a period of years, from pre-adolescence to young manhood. Others of the boys in The Genesis Children are also clearly identifiable, however. In Usenet afterlife, Mr. Glawson is the most prominent of the Lyric models. Was he preeminent at the time? In The Genesis Children, he supposedly has only a single line of dialog. However, one of the films, Peter and the Desert Riders has his name in the title.
Also, the Hollywood magazine Zipper had in its June-July 1972 issue, along with a review of The Genesis Children, an item called “Zipper's Roommate of the Month: Peter Glawson (Young Star of "The Genesis Children")." Perhaps he was regarded as something special even then. An August 27, 2006 eBay listing for a copy of the issue says it contains "an exclusive interview via telephone with young Peter Glawson, star of Genesis Children entitled Genesis Child (with six tasteful photographs, including centerfold)."
He appears to have been a frequent presence at the Lyric studio and the pool with the cinderblock walls, also Mr. Byars’s house, in the Hollywood Hills. One of Lyric's early magazines, Coq d'Or, says "Peter rarely wears clothes around the studio."
Usenet posts by those who claim to know Mr. Glawson uniformly declare him to be heterosexual. None of the Lyric International films or magazines show him in sexual activity; indeed Lyric produced nothing showing anyone in sexual activity. Lyric produced only “physique” photos, although Guy Strait, associated in a distribution operation called DOM/Lyric, did produce pornography including child pornography.
The Lyric producer mentioned above did confirm that Lyric used as models some boys who also worked as call boys. The highly unreliable Robin Lloyd affirms that a "Peter, a thirteen-year-old and one of Byars's favorites, still commands a high price in the chicken market" (Lloyd, Robin, For Money or Love: Boy Prostitution in America, Ballantine Books, NY, 1976, p. 79). On the same page he affirms that The Genesis Children includes a Hawaiian boy named Guy Sommers, which can be disproved by consulting IMDB or the picture on the cover of the VHS tape.
There is even a published story that two of the Lyric boys participated in a tryst with J. Edgar Hoover and his assistant. .
That incident involved a boy who was 15 in 1969, and “another boy”, and again the source is unreliable, in this case the same man who circulated the tale of Hoover dressing up in drag. There is simply no evidence that Mr. Glawson did any more in front of Lyric’s cameras than take off his clothes. Nor is there reason to believe that anyone else ever did. While there were young men known to Lyric that did engage in sex for pay, there is no reason to believe that Mr. Glawson was among them, and those who seem to know him declare that he was not.
Boyhowdy’s 1999 post declares of Peter that
We do know for a fact that he is still alive, and in fact was the benefactor of Harlan 'Slim' Pfeiffer's estate, including (sources say) having acquired most all of Slim's collection of negatives and photos from the Lyric days. It is also reported that he bought up, or otherwise acquired, the rights to all the nudist stuff, including the films, most of it which was owned by Falcon Studios, and the remainder by a couple of photographers. It is our understanding that Peter is still in contact with the Dom and they remain friends.
Peter Glawson has made some appearances as an adult, including on some cable TV talk show a few years ago. He apparently is unwilling to say much about his childhood stardom or give out information about any of the other boys, possibly to protect their privacy. He did acknowledge his acquisition of the original photos and indicated that The Genesis Children, as well as videos of the home movies, were to be re-released, which has in fact happened.
Some of what Boyhowdy has to say is verifiably incorrect: he merges the three separate figures of "the DOM" who was Guy Strait; Billy Byars, Jr.; and the Lyric producer referred to but not named here.
Other Usenet posts from 2001 describe Mr. Glawson as happily married with children, and having no regrets about his early career in photography.