It should be relocated at Archie (The Victorian Age) because the character first appeared in the audio The Victorian Age. He was only mentioned in The Twilight Streets.
Talk about it here or check the revision history for additional comments.
Archie was a Scottish man who worked for the Torchwood Institute in the 19th, 20th and 21st centuries. Due to an alien attack and subsequent recovery, he did not visibly age, and appeared to be around 80 years old for over a century. (AUDIO: The Torchwood Archive)
He was the director of the Torchwood Institute's London branch in 1899. On 17 May that year, he was rendered incapacitated when he was rapidly aged by an alien creature which fed on youth, leaving the position of Torchwood London leader vacant. (AUDIO: The Victorian Age) He eventually recovered, but never got his looks back. However, as a result, his appearance also did not change for over a century.
Archie was, according to Jack Harkness, a "very strange man". (TV: Everything Changes) Given his age, he referred to himself as a "dinosaur" by the second half of the 20th century. (AUDIO: The Torchwood Archive) Called "Old Tartan Archie" by his colleagues, he did not have the hang of computers, and exchanged bizarre emails with Owen Harper. The words used were "interesting and not always used in the right context," and he referred to himself in the third person, which Owen attributed to either eccentricity or whisky. His ineptitude with email caused him to send a picture of the Loch Ness Monster to the Glasgow Herald. (PROSE: The Twilight Streets)
Behind the scenes
Jack Harkness first mentioned Archie (not by name) in the television story Everything Changes. John Barrowman has suggested at a public appearance that if he ever appeared on-screen, David Tennant should play him in heavy make-up.