KHS today is a mass market bike manufacturer making everything from slightly better than Wally world bikes to high end racing bikes. There's not a huge following for them as I don't think any teams have ever used them in big time racing. I've owned a few and find them to be excellent bikes.
The Campy GS equipment would be logical on a 531 frame, but that's no guarantee. I've seen other Olympians advertised as having 531 frames. Best way to find out is to email KHS from their website, with your serial number, and they'll probably be able to tell you.
Nice bike.