I had one of those (the re-issue in the photograph), very nice, one of the most accurate mechanical watches I ever owned. Only thing I didn't like was that it was a bit on the heavy side.
Here is some information about the original
http://www.mwrforum.net/forums/showthread.php?t=22887
Here is some information about the re-issue
http://www.cwcwatch.com/1970-chronograph-mechanical.htm