Update: According to the Louis Armstrong Archives, only portions of these performances have been issued over the years. "Struttin' with Some Barbecue," "Over the Rainbow" and "Sleepy Time" are completely previously unissued.
The on-air host for these KCBS broadcasts Bob Goerner arranged for these "line checks" to be recorded at the radio station where the dedicated broadcast phone line brought the signal from the club. Bob preserved the tapes for decades, loaning them out occasionally for issue by small record labels.
After hearing my local program of classic and traditional jazz on KALW-FM in San Francisco, Goerner made them available to me for broadcast in the early 1990s. After Bob passed, the tapes were acquired for preservation by the San Francisco Traditional Jazz Foundation with the assistance of Ken Ackerman, another former KCBS employee, and they are now at the Stanford University Braun Music archive.
These .mp3 files are taken from the original 15 ips monophonic tapes in that collection.
Surprisingly many of these musicians were living in the Bay Area or on the West Coast at the time: Earl Hines and Jack Teagarden both lived in Oakland during the late '50s and early-'60s. Kid Ory lived variously in L.A. and Petaluma, a chicken-ranching community north of S.F. Muggsy Spanier spent his later years in the artistic community of Sausalito just north of San Francisco.
MUGGSY SPANIER leads his band and the Hines-Spanier All-Stars** on several broadcasts.