I have seen Z gauge in dolls houses. Nothing new there, but this has given me an idea(gimmick)
With a box car , doors in centre, some of the front panel removed so you can see what is happening. A wagon turntable in doorway(now wonder where you could get one of those
Small loco/forklift truck(not difficult in Gn15), carries box into wagon, turns 90 degrees and moves box into box car. Some form of rack to hold box. maybe some way to raise or lower that as well, from back out of sight. Box deposited on racks and returns for next one. Maybe a traverser to move track from side to side, again controlled out of sight.
Once the box car is full, reverse process and empty the boxcar.
Narrow gauge Francophile interested in 1m, 60cm,50cm , 40cm and smaller gauges . Build in scales from 1/6th to 1/24th. Also 1/32nd and 1/35th using 16.5mm track to represent 50cm and 60cm gauges. http://www.rue-d-etropal.com