These kind of projects are fun to learn on. I'm in the "try it and see" camp.
The brazing is probably the best bet. I still see a fair amount of old braze repairs on cast implement parts. Try and find out exactly what kind of iron it is. If it's white iron I don't think you'll have luck with conventional rods over brazing. If it's malleable or ductile the regular rods may have some success.
I do my own repairs but don't consider myself a "welder", nor do I play one on TV!