rj stands for rideaway junior, and 58 is the year it was made. here is a picture, the one on the left is an rj58, the one on the right is a suburban. the low slung front axle would lead me to believe yours is a suburban. but i'm no expert. others here know far more than i do.
edit: the picture on the far right in the first row show both tractors. the link is to the website, not just the picture.
http://images.google.com/imgres?img...ev=/images?q=wheelhorse+rj58&gbv=2&hl=en&sa=G
edit: the picture on the far right in the first row show both tractors. the link is to the website, not just the picture.
http://images.google.com/imgres?img...ev=/images?q=wheelhorse+rj58&gbv=2&hl=en&sa=G