There is no way to contact the manufacturer of any of the hay racks we're using.
We inherited the feed racks when we purchased the farm 4 years ago. Based upon how the iron rack looks it is old. Some of the hay racks we're using are repurposed handmade (using hand tools) hay racks for the draft horses used on the farm from before there were tractors. The wooden bars in the wooden hay racks are held in place with cut nails.
You know, back when hay was cut and brought in from the fields using horse drawn equipment and then put up in the barn loose using a hay fork hanging from a track in the peak of the barn.
Making hay ca 1900