I found these wheel weights for the TO-30 on Ebay. Wanted to put these on the one I just bought with the bucket so I would have extra weight on the back of the tractor. Do you know if they would fit OK on the rear wheels? http://r.ebay.com/XjW7oQ.
The weights you purchased appear to be MF # 677 206 weight segments. These segments are designed to be used with either or the two styles of power adjusted rear wheels. Each style of wheel takes an adapter plate that gets bolted to the wheel center and then the first segment, like those shown in the picture you sent get bolted to the adapter. Additional segments can be bolted to the first segment and then to subsequent segments to form a stack of weights. If your TO-30 has either style power adjusted wheel and you have the correct adapter plate you can install these weights on your tractor.
I am attaching parts book pages so you can see what the power adjusted wheels look like and what the segments, adapter plates and mounting hardware look like. If your tractor does not have the power adjusted wheels you will not be able to use these weights. There is a similar style weight segment and adapter plate for the 13 x 24 wheels with the cast iron center but, the weight segments are not interchangeable with those for the power adjusted rims. If you have the manual adjust 12 x 28 rear rims there are several aftermarket weights available including those that fit on top of the rear axle behind the fender. Another popular style attaches between the rim and the wheel center. If you are unable to use the segments you purchased they should be fairly easy to sell.