Sometime in the last year, I bought a pair of Atlas GP40-2's painted and lettered for B&M. They are beautiful, and they run very well, but the couplers are something I've never encountered before, and they don't mate with anything else I have.
They are body mounted, which corresponds to the exploded diagram on the insert that came in the box with the model. However, the diagram shows standard Rapido couplers.
These are ***tiny***. They look roughly like MT couplers, only the "thumb" doesn't stick out at a funny angle the way it does with normal N-scale MT couplers, and they're maybe 1/2 or 2/3 the size of N-scale couplers. Also, the fronts of the knuckles are flatter (when viewed from above). Looking at them with a magnifying glass, it looks like that used to have metallic trip pins (or something), only they've been clipped off.
Would these somehow be MT Z-scale couplers? Does Atlas ever produce models using those?
Part of the problem is that they are *so* closely-coupled that even just the two of them together can't go around a curve on my Atlas (!) sectional-track layout without one of them flipping off the rails.