If you type in "replacement tractor wheel weights, Texas" you'll find a couple of places that cast and sell knock off wheel weights. Look and there will be pics of the weights you have but painted black. It also gives weight, models used on and measurements for positive ID.
I often do this to identify orphan weights. Yours should be easy to do.
This is a good resource, Sixdogs. However, I wan't able to find anything similar on that site. I did see the typical Ford weights that I am familiar with on there. I haven't come across this style before.