Is this an external regulator?

[Nima]

Hey guys:
These questions may sound stupid but I won't know if I don't ask!. In the first pic, is this an external regulator box? if it is, I don't undrestand the wiring on it. I read lots of thread about external regulators and the fact that they have 4 wiresbut this one is differnt or may be it is not regulkator!. Help me out please. On the second pic, if that was external regulator, then this is external regulated alt, is this right? if it is not, can you tell what kind alt is this? I plan to change this alt with the one on the pic #3. I read the threads about wiring from external to internal regulated alt, I just need to identify the wires since none of them look original. Thanks. Nima.
By the way, I don't have warning light, but I have guage.