Either here or on one of the chats, someone (Laura maybe) was asking about Jack's radio appearance(s) prior to the Canada Dry programme.
I checked through the old NY Times Radio listings on-line and the only one I can find is the famous one of Tuesday, March 29, 1932:
WABC 860 Kcs.
8:45 p.m.—Ed Sullivan Comments; Berger's Orch.; Jack Benny, Monologues.
Naturally, .pdfs of NY-Chi-LA radio listings have been on-line for ages but I only recently stumbled across them by accident.
http://www.jjonz.us/RadioLogs/
Yhtapmys