I have an Oliver 500, Diesel engine tractor that I plan to offer for sale through a local newspaper.  I live near Calhan, CO.  What is the fair market value of an Oliver 500?  It has new rubber on the rear and one of the front tires.  Hydraulics leak, and one of the fenders is dented, otherwise it is in good condition.  It ran well when I parked it a year or so ago (in a barn), but I have not tried to start it recently.