400E Trim Level - What does it mean?

Nickel vs. Brass is referring to all the piping and bands on the boiler. I am not a Std Gauge expert but I think back in the day the Nickel trim was later and the brass was earlier.

The description "nickel trim" in the bulleted notes for the 11-1028 is a misprint (not uncommon for MTH).  That engine is brass trim.

The wheels and drive rods are always nickel, regardless of trim.  The trim items are headlight, bell, smokestack, sand dome, piping, plates, etc.

 Nickel trim:

Brass trim:

 You may have a hard time finding a 400E in black with nickel trim.  Most black and crackle black have brass trim.  The nickel trim model above is in gray enamel.

As far as I know, the green State Cars are trimmed in brass, like the black 400E.  The "nickel trim" in the bulleted list for the green state cars is also a misprint. MTH just copies and pastes that list for everything, I think.  

If you go with the brass trim you should be okay for both the 400E and the cars, but if you have someone you talked to at MTH, you might check on that.

Hojack - Looking at each model side by side like that, I can now tell there's a major difference between Brass trim and Nickel trim.  I think my confusion stemmed from my conversation with MTH that only a few of the trim pieces were either Nickel or Brass, in this comparison, it's all of the trim pieces.  Going forward I'll remember the misprint you mentioned and rely more on what I see on the locomotive and not what's printed. 

Many thanks, Hojack!!!!