My trade guide puts it as a 1991 model. They did a fairly good job as long as you had a good sections and guards. They have fell in value as the market has moved to disk cutter bars.
When you tow it make sure and lock the swing on the tongue. They can drift out or in without a tractor on the hydraulic cylinder. I remember there being a swing lock but not if it was a pin or just a valve on the cylinder.