I recently bought hooks of a different brand than I normally do, and I did it on-line. I bought them in a different brand because Mustad stopped making them. The reason I bring this up is that their ideas of a 1/0 hook are radically different. I have run into this before, but this was the worst case of it I have ever seen. Here are the Mustad and Daiichi hooks side by side. Both companies call them a 1/0 hook.
I just ordered the Daiichi hooks in a 5/0. When they arrive I will post a photo of them side by side. These are the hooks I use most for my Pike flies. If any of you have run across a situation like this, maybe you could post it here so nobody ends up with hooks the wrong size for what they want.