I started on a project a couple years ago to do something along the lines of what you want.
My plan was to cut the Newsline MP3 down into managable chunks, and build a "playlist" for another on air playback script to use.
In the playlist it would be an ID cart maybe every third or fourth cut.
Got most of if working. I'll have to return to it one of these days.
Take a look at this : http://mp3splt.sourceforge.net/mp3splt_page/home.php
This will cut up an MP3 into segments based on time, or where it finds a definable length period of silence.
Somewhere on that site is buried a Linux command line version. Or do a Google search for "mp3splt command line".