I have seen wagon, and buggy, rims that were poor quality wrought iron, and I have seen some that are quite good quality. I am using a very narrow buggy rim at present, that is great. It has almost no inclusions at all. I once had a heavy freight wagon rim, about an inch and a quarter thick, that was so full of inclusions that you had to heat the pieces and fuller them in both directions to beat all the inclusions out.
Hungry Horse