This was provided by Edward Sehlhorst, an archivist for the Old Time Radio Reasearchers Group www.otrr.org.  Their mission is to aggregate all available materials relating to each radio series broadcast during the Golden Age of Radio and provide it to the public at no cost via www.archive.org and other outlets.

He is currently engaged in the project of "The Halls of Ivy".  In that series, one broadcast, "The Snowman" from Feb 10, 1950, episode 006, announces a congratulatory message to WTIC celebrating their 25th anniversary.

The above link is to the closing credits. Here is their documentation:

02/10/1950 006 The Halls of Ivy     The Snowman

Sponsored by:  Joseph Schlitz Brewing Co.

First Line:  Five people didn't go to bed at all last night here at Ivy. Grogan, the campus policeman who was making his rounds. Two sophomores and a freshman who were investigating certain mathematical phenomena, such as the odds of drawing to an inside ...

Plot:  President Hall is disturbed because his students haven't built a Christmas snowman in front of his house.

Credits:  Ronald Colman, Benita Hume, Alan Reed, Gloria Gordon, Arthur Q. Bryan, Don Quinn (creator, writer), Walter Newman (writer), Nat Wolff (director), Henry Russell (composer, conductor), Ken Carpenter (announcer),

End of Show:  Ronald Colman presents a PSA on behalf of the Heart Association.  Ken Carpenter announces Congratulations to Connecticut station WTIC, on their 25th Anniversary.  Network following program is We The People.