The six-pointed star is a casting mark. See this thread :-

http://pub37.bravenet.com/forum/static/show.php?usernum=3155626639&frmid=16&msgid=1230292&cmd=show

It sounds as if your casings have been re-stamped but the best way to find out would be to post some high-resolution photos here as the experts will be able to say if they are WD-type.