http://www.coinbooks.org/esylum_v03n45a08.html
Copies are a dime a dozen, but the restrikes are actually collectible and
worth $2,000 - $3,000.
There were only four originals made and all are accounted
for, although I don't personally know the whereabouts of
the fourth specimen. One is in the collection of the American
Numismatic Society in New York, one in the hands of a St.
Louis collector, and the Jefferson Davis specimen is in the
hands of an Arizona collector. The fourth was sold to a
private collector about 25 years ago. The restrikes were made from the original dies by striking them on a planed-off 1861 Half Dollar.
The diagnostics are:
1. Lighter in weight than a real 1861 Half
2. Reverse shows pitting from die rust
3. Obverse is flattened from the blow of the reverse die.
........................................................
In early 1861, the President of the Confederacy, Jefferson Davis, authorized production of a Confederate Half Dollar. This was accomplished by taking ordinary (USA) Half Dollars with the Liberity Sitting on the obverse, removing the reverse motif, and adding a shield with seven stars (only 7 states had joined by that time) and adding the words "CONFEDERATE STATES OF AMERICA -- HALF DOLLAR --. Only four were ever made. The obverse shows a seated woman looking to her right with 13 stars around her and "1861" underneath. The coin shown here is not real but a reproduction. A real coin looks somewhat like this but with some difference in the details especially around the bow on the reverse.
In 1879, a man by the name of Scott came into possesion of the original reverse die. He then obtained 500 1861 USA half dollars and removed the reverses and stamped them with the Confederate die. He made 500 of these "restrikes". The restrike can be identified by an imperfection in the word AMERICA between the letters E and R. The obverse is also slightely flattened.
He then made 500 more coins but then used his own obverse which consisted only of words. The beginning words are: "4 ORIGINALS STRUCK BY ORDER OF C.S.A. IN NEW ORLEANS 1861
http://www.csacurrency.com/csacoin/csa50ct.htm