I also go with taking a blood sample and having him DNA tested. I have heard that some of the rare breeds have a DNA database to help with breeding, identifying ect. Its definitely worth a shot. I also know someone years ago that found a horse at a killer auction, and ended up finding out that it was a rare breed of horse, and registered, had been someone's broodmare at one point, though she didn't look like much when she got her unfortunately. She ended up being an awesome horse, and I really wish that I could remember what breed she was. He is absolutely gorgeous, and I wouldn't geld him, especially if is is an Ardennes, color aside, the breed is already rare, and why take a potential great specimen out of the gene pool just because of color. Hope you have fun with him.