Well, apparently the radio show started in the 1951 and ran to 1960 (Python starting in 1969). The cast included Peter Sellers, Spike Milligan, and Harry Secombe, with Michael Bentine having been involved before the height of the group's success.
http://www.thegoonshow.net/history.asp
All the Pythons (with the possible exception of the resident American interloper) speak of having listened to the show when young.