OEM 'N' rear rims consist of the outer wheel with a center disc to mount to the axle hub. There is no 'extra' wheel weight device attached. All 9N and 2N rear axle hubs used the same center disc, then the 8N came out with a completely different wheel hub bolt pattern and the two centers do not interchange. Center discs will interchange with the wheels however. The original early 9N came with 6-loop Rear Rims, in the 8 x 32 size. Tire size was 9 x 32. Then Ford introduced their famous "Hat Rim", still in 8 x 32, and shortly after introduced a smaller rim, the 9 x 28 Hat Rim. It now used the 10 x 28 tire. Today the 10 x 28 is sold as the 11.2 x 28 -same animal; they just measure differently now. For the N-Series Tractors, wheel weight ballast was by adding Calcium Chloride into the tubes. There were some aftermarket companies, like the one pictured, that offered solid wheel weights. Ford never made a wheel weight for the N-Series. It wasn't until the Hundred Series came out that they made and sold the famous 'pie-weights' but those were designed for use on the more rugged 600, 700, 800, and 900 models. As already mentioned, if your 9N tires are loaded with Ca Chl, or some other liquid, they will be extremely heavy. You can check if loaded by rotating the wheels around so the valve stem is on the bottom a the 6-O'Clock position, remove the cap, then press the pin in. If any liquid is in the tire, the liquid will squirt out. I use a more modern product called Rim Guard ® ™ or Beet Juice because it is made from sugar beets for ballast. I have been using it since the mid-90's about when it was first released. It is guaranteed safe for ferrous materials, guaranteed not to rust. It works. Beet Juice has a weight of approximately 10 pounds per gallon. I have 27 gallons in each of my rear 11.2 x 28 Firestone work tires and have never any problems with it.