Z Scale 80' Fluted-Side 8-6 Sleeping Car (RI)
This is a model of an 8 Roomette/6 Double Bedroom sleeping car used on the Rock Island. The trucks/couplers I suggest for this model are Micro-Trains #959 or 959-A (aluminum).
I print my models on a filament (FDM) printer. That's what they're designed to be printed on. For weight and strength the roof should be printed at 100% infill. The body can be printed from 50% to 75% infill for weight. Print both pieces flat-side down and no supports will be needed.