These are Kato Mini Diorama compatible bases. Both original straight and curved bases have been remixed from the work at https://www.thingiverse.com/zephyr334/designs and two new bases have been created, one to support an S62+S62F for rail power, and another base a reversed curved based.
The author remixed this model.
Both originals have been remixed to add component information in the interior and to extend the screw hole shafts so that the screw is not just hanging out loosely.
New models have been created, one to include the short power track S62F together with an S62. Another model is a reversed image of the curved base R183.