After looking for rear wheel weights for a NH TC-45D, I finally settled on weights from Taylor Foundry a little while ago. A link is at:
Taylor Foundry-Manufacturer of Gray Iron Castings and Tractor Weights-Serving the Agricultural, Industrial and Construction Industries. They were less expensive than New Holland weights but the shipping of course added significantly to the price. They said they would paint them to match the tractor, I understood but the white they used doesn't match the NH off white color.
Also, the company doesn't seem to know or care about proper painting techniques. One set were stuck together as if they had dipped them and then immediately set one on top of the other to ship!!! It took a lot of prying with a large bar to separate them---and that of course damaged the paint
. I really don't like rusty looking weights on a nice looking trractor so I am going to paint them Blanca white. I will have to figure out an easy way to put them on (one set of two on each wheel, each individual weight weighing 105 pounds).
They will sell them to any tractor dealer that can sell new tractors, I believe I was told.