Of all the podioplays I've listened to, “Jake Sampson: Monster Hunter” comes closest to what I think an old-style radio play would take.  If memory serves, “Claybourne” was actually produced for New Zealand radio, but it is not an old-style radio play.

Serial 1, Part 1 (2007-09-14): The Hyborean Gate
Serial 1, Part 2 (2007-09-14): The Hyborean Gate
Serial 1, Part 3 (2007-09-14): The Hyborean Gate
Serial 1, Part 4 (2007-09-14): The Hyborean Gate
Serial 1, Part 5 (2007-09-14): The Hyborean Gate

Serial 2, Part 1 (2007-09-20): Jake Sampson and the Tears of RA
Serial 2, Part 2 (2007-09-20): Jake Sampson and the Tears of RA
Serial 2, Part 3 (2007-09-20): Jake Sampson and the Tears of RA
Serial 2, Part 4 (2007-09-20): Jake Sampson and the Tears of RA

Serial 3, Part 0 (2008-04-11): The Adventures Continue
Serial 3, Part 1 (2008-06-05): The River of Woe
Serial 3, Part 2 (2008-07-10): The River of Woe