Listening to a compilation CD set of Los Panchos this morning (Columbia recordings on Mexican Sony), and with a little investigation, it seems the group was founded in 1944 by Alfredo Gil (with the group until 1981, died 1999), Chucho Navarro (with the group until his death in 1993), and Hernando Alviles. The third member changed at various times over the years.
Apparently there is more than one Los Panchos performing today, with somewhat tenuous connections to the real group.
The New York Times obituary of Alredo Gil:
http://www.nytimes.com/1999/09/16/arts/alf...latin-trio.html
Alfredo Gil, 84, Member of Popular Latin Trio
By JULIA PRESTON
Published: Thursday, September 16, 1999
Alfredo Bojalil Gil, whose mellifluous guitar added honey to the sweet sound of the Latin trio Los Panchos, died on Friday at his Mexico City home. He was 84.
Mr. Gil, who was known by his nickname, El Guero, which means fair-haired in Mexican Spanish, was the last surviving member of the singing group.
He was born on Jan. 5, 1915, into a musical family in a musical land, the Gulf state of Veracruz. But to find recognition he had to travel to New York and its Latin nightclubs. On May 14, 1944, the trio made its debut with Mr. Gil on guitar and another Mexican, Jesus Navarro, known as Chucho, singing harmonies. The heart-melting lead voice belonged a tenor from Puerto Rico, Hernando Aviles.
Mr. Gil said they agreed to call the group Trio Los Panchos after the Mexican revolutionary, Pancho Villa, who they assumed would be well-known outside of Mexico.
...
To lighten and smooth the group's sound, Mr. Gil chose to play a small guitar with a pleasing hum, a requinto. The instrument he pioneered became essential for romantic troubadour trios.
Los Panchos made more than 300 records, ... and appeared in some 50 Mexican films. Their recordings have continued to sell tens of thousands of copies each year. While the lead singer frequently changed, Mr. Gil remained with the group until he retired in 1981.