My WA Beretta 92FS Inox is the most accurage GBB I have, and it's bone stock. Unfortunately, I have never been able to locate a metal slide for it, so I never use the gun for fear of breaking it with propane. It goes back to what safx said. No parts available.
But when it comes to the cosmetics, it's the king of my collection. It's an absolute beauty of a gun. And it's actually hard to tell the gun is plastic when handling it because of the incredibly metallic look and hefty weight. I really wish I could locate an aluminum slide for it so that I could actually use it. I love that gun.