Well, I guess I was right:
It was what I said. Some material called Material__3 had no _ExtMtl version. That caused the glitch.
From what you say, this would complete Roy to be released. But I want you to notice some thingies:
Cape problem:
Something is different in the rigs of the parts of the cape, and graphical problems like this happen sometimes. Not very noticeable though.
Normals problem:
This is not a metal problem, but a normal one. The metal texture is shown depending on the normals in the vertices of the objects, and when they're different in the junctions, metals look bad. It can be seen in certain stages without the metal, depending on the environment used.
With this said, I have to say that the rig seems perfect, the eyes work fine (well, yellow eyes would need some coloration, but that's not big deal) and the hack is good overalls.
But, being ROY, from Melee, and probably the best Roy we'll ever find in the vault anyday (I don't guess anybody else is rigging him again after yours), I have to say it deserves to be a little bit better. So, I propose you something.
Option A: Release it as is, the issues are small and most people will be fine with it. I would make some personal fixes due to my perfectionism, but it would sure get a place in my SD.
Option B: Release it as is, etc etc, but in a near future I will revamp it so it uses less textures, more clear material names, and repair the small issues in the cape and in the normals. When I'm done, you upload your vault with the changes.
Option C: Do not release it. Take your time, make people wait a little more, and perfect it. Once it's perfect, just release it.
Option D: Do not release it. Your hack is awesome, needs some fixes, but you have many other projects in hands and you do not like to get stuck in a single one. Let me finish it and release it when I'm done with the fixes.
Option E: Any other option you can think of O.o
Whatever you choose, it's okay, I'm just caring about the final product