Thanks, interesting info.
Found a Gruen Curvex. Cool.
I doubt "old" Gruen has anything to do with the modern Gruen. The new ones are $150 rep/Invicta/Sandoz quality watches... obviously assembled in Far East. They have basic ETA movements inside. Seen a few of them in the watch forums. Probably just someone in Far East using their brand name, just like Henri Sandoz (that used to be a respectable Swiss brand in the "old days").
http://cgi.ebay.com/Mens-See-Thru-Automati...1QQcmdZViewItem