Thanks for flipping it over. Its design doesnt make for an easy conversion as you might hope. Tight to wheels&gauge, connects to the shell via tabs and a step in front of the cab is there at the porch, for a start. I think it might be harder to go Build a loco than floating the porches prototypically. With the cab raised up an 1/8th" to clear the porch step things look promising though. A set of top and bottom bolster plates with pivot rivet sitting between cab and truck. ..reuse the tab and slot system on your pivot plates. 2rail carpet drive? Or even driveshafts, 2r to 3rflanges. Those side frames and faux wheels can hide a lot if you could get them swinging.
On the box lid there is a white makers mark. Could you get a better shot of it? (I like logo aspect and scroll the old Japanese lists sometimes just to look at them.)