The key pic internally is to take the inside of the hole you can just see in the first pic. Assuming its a mechanical centre there are ramps inside that determine if it's 1, 2 or 1.5 way, they look like |/, \/, or a halfway between those 2 respectively.
Also there will be a ratio stamped on the main gear as well, something like 37:9 which is the 4.11 diff. edit, cancel that, I can see you have that in the 3rd pic
I don't know how to tell the brand of the centre, others might, but personally I don't think it matters too much