Diecast Direct in Frankfort, KY had some simple pre-made 3-D printed parts in 1:50 scale when I visited their store last week. 3000toys.com in MO & DHS Diecast in OH also have simple pre-made 3-D printed models in 1:50 scale. By simple models, I am referring to trash dumpster, traffic cones, porta potty, etc.,, stationary diorama / layout accessories without many working features.
These are just my opinion,
Thanks,
Naveen Rajan