The Key/Nakamura ATSF Mikado is very much similar to that manufacturing tandem's NYC H-10 Mikado model (released in the same year). Both are fine looking models that perform admirably. About the only differences I can detect between the two (beyond the shells) are minor variations in some of the valve gear.
The chassis is all-metal and fairly minimalistic (with most of the heft being provided by the locomotive shell). The motor is an open-sided 5-poler. The second set of drivers (from the front) is equipped with traction tires. Right-rail pickup is provided by the right-side drivers (excepting the TT-equipped one, obviously). Left-rail pickup is provided by all six left-side tender wheels (with current transferred to the motor via a stiff wire on the drawbar). All the rest of the wheels are electrically neutral. The center two pairs of drivers are geared (with the outer two pairs being turned solely by the cranks). All gearing is metal. Wheel flanges are low-profile and suitable for operations on Code-55 track. A dummy knuckle coupler is mounted to the pilot. No tender coupler is provided, although there is a screw hole for mounting a Micro-Trains coupler box. There is no lighting. The drawbar has two different holes in it, allowing for a bit of flexibility in tender spacing.
This steamer is a very solid performer - overall, it runs extremely smoothly and quietly. Slow speed creep is exceptional. It has no problems navigating 9.75"-radius curves, nor does it have any problems keeping all of its wheels on the rails. OK, the top-end speed is excessively high. But, given the era in which it was produced (early 80's), pretty much par for the course. The only real fault I can find here is with that tender drawbar connection (vis'a'vis conducting current). The end-result is just a bit of occasional jitteriness. No, not horrible, but definitely noticeable. With a solid wire running from tender to engine, this thing could probably run just as well as a Kato Mikado. All in all though, a very nice looking and fine running model, and certainly worthy of joining an operational fleet.
To remove the locomotive shell, unscrew the screw underneath the pilot truck and the two screws at the back of the cab. The shell should lift up and off at that point.