I have owned one dress watch in my life, and it was a Seiko quartz, so my experience is less than limited, but I didn't expect any dress watches had screw on backs. I haven't even seen a screw on gold colored dress watch. Is that common? I am not convinced still that this is a screw on back. Look VERY closely around the area where case meets back to see any slight notch. Use magnification.
So assuming it is threaded, it is likely one of those that haven't been opened in decades...or ever, and the gasket is now practically one with the threads. I tried the super glue thing once, and the glue was not strong enough to open the back I was torquing, but it might work for others.
My advice is still to find a watchmaker who can open it. There are watchmakers, and there are the guys in the mall who change batteries, and there are a class of guys calling themselves watchmakers who are more like amateurs. (ex: a guy who told me he needed my watch for 2 weeks to use an old family recipe to open it. I didn't leave it with him.) Find an actual watchmaker. Find someone who has something like this:
