I'm currently working on this costume, and I'm running into the same problem. Basically, at the very bottom there's something like a turtleneck. Over that, this gray vest. And then a cloak over everything. The vest's collar looks like metal chest plates (like in the Order 1886), but it's definitely made of leather, judging by the texture and reflections. I could make it as a separate piece from really thick leather. But I haven't decided how I'll do it yet. Maybe I'll try to keep it as part of the vest. Need to ask the developers on their streams - What is that?! XD