Hi to all I designed some new speaker cases that fit into the n scale Atlas GP40. Two designs- one for mounting in the front, and one for mounting in the rear. The file is .stl, so usable for most 3D printers. https://www.tinkercad.com/things/1xf9DDmnJDD-speaker-cases-for-atlas-gp40-front-and-rear-mount Have fun!