Well to help some, I've seen NS 4000 in person twice. And yes, I do own 4000 in MTH. The model is the correct paint and the detail on the engine is correct as well. They even put DC to AC AC44C6M on the side under the cab. Only thing missing on the MTH version is the small NS patch under the cab window. I guess the only factor I had was the horn. MTH uses a K5LLA horn audio as the real 4000 has a P5, which is fouled now. Anyway, the 2 photos I took below.
