[camarojoe]

I believe there were at least 2 different suppliers for the rosewood wheels, as i've seen some that have a circular depression on the backside with a letter code molded into the plastic, similar to what you will often (but not always!) find on the lower backside of a "comfortgrip" style wheel. Most rosewoods don't have any markings on the back at all, but I've seen some that do. As Charley noted, the color varies as well, as does the amount of black streaking or graining in the plastic. Some are almost completely solid color like the one the OP has, and others have a ton of swirling and streaking of black throughout.