I went to Hy Capacity's web site (http://www.hy-capacity.com/).  I'm sure it is listed someplace on there, but that is one of the more aggravating sites I've tried to use recently. It reads like you have to buy through a dealer only .  BUT I did a quick search for tractor buddy seat and found one at Sloan Express.

It would be interesting to know if Sloan's sales jumped because of this one mention on AgTalk?