The microphone shown here is of the earliest type, from the early 1950's.  Note the purplish silk covering the openings in the shell.  Later versions used gray foam which was probably better acoustically, but didn't look as nice, and will inevitably disintegrate into a gummy mess.

While the 55S is not at all rare, the fact that this microphone was found unused in its original box is unusual and, for that reason alone, its inclusion here is justified.  The original list price was $72.50 in 1951 (it is close to $300 now). 

In 1993, the USPS honored the Shure 55S microphone with the release of this postage stamp.  Appearing with the microphone is some obscure singer whose name I forget.  (Just kidding, Elvis fans!)  

Actually, the microphone on the stamp is only an artist's conception, and is not an exact depiction of any production microphone.  Because of this stamp, the 55S (and several similar Shure models) have come to be known to collectors and performers as "Elvis" mikes.

This supersized Shure microphone found its way onto the back of this KNUZ mobile unit in the early 60's.  I wonder if it was actually a speaker cabinet?  Anyway, the location is Houston, TX, and the vehicle is a rare Corvair pickup.

This picture appears courtesy of the Center for American History, The University of Texas at Austin.

Visit the Houston Radio History website for much more on the history of radio broadcasting in the Houston area, and some other great pictures.