http://doppels.proboards.com/ This has been on my
mind for awhile but I am quite certain that shock jock Howard Stern was replaced
in 1998, a year after his movie Private Parts(1997) was released.
The smoking gun is the chin. The fake Howard has a larger chin that just cannot be explained away. Howard's voice also got deeper. If you have listened to the show in the last 10 years, you'll know when they used to play old shows from the 90's, Howard's voice seemed much higher for some strange reason.
Fake Howard, with the larger, longer chin
Howard Stern 1992 voice:
Christ mocking (Crucifixion)