Don't use a torch.
It's my opinion that if you want to repair it, you should use a mig or a tig. The reason why is to minimize the heat transferred to the surrounding frame area, which could weaken it. However, after re-reading your post, I noticed BRONZE. If you just want to plug the hole, that should be fine but keep the heat to a minimum. You may want to use some wet rags or "that heat sink play-dough compound stuff" to help maintain the heat in just the repair area.