Just a cute little industrial critter that will fit fine on a bogie of an old bachmann 44-ton or 70-ton switcher (the old twin motor version). Or build it as a dummy, point bearing axles will fit.

These little diesel-electric engines from the 1940's-1950's will look fine at any industry, mostly in the US but a few made it to Belgium. Usines Gustave Boël in La Louviere operated a whole fleet of these things, Fafer in Charleroi had 1 and another one went to Amerlex in Antwerp and later to the ARBED steelworks in Luxemburg where it served in the blast furnace department. Some pics of the real thing (I guess it was out of service at that point as the cab looks pretty badly burnt) can be found here: https://rail.lu/materiel/a160.html
I think it's a rather interesting version with the longer hood and all the performance parts added (double air cleaner, fat exhaust) and of course I had to have one to go with the ARBED slag ladles.
https://www.thingiverse.com/thing:5454140
https://www.thingiverse.com/thing:5454048

You can of course swap out parts with the US version as I think a similarly modded version would look fine in the US as well. (link: https://www.thingiverse.com/thing:5988698 )

assembly:
glue the hood to the frame, test-fit the bachmann-bogie, glue the cab in place, test-fit the hood top (should fit snugly on the hood without glue), maybe a decoder? some lights? stay-alive capacitor?
I made the top light as a separate part, so you can replace it with an LED if you want working lights. The small lower lights can be fitted with tiny smd-LEDs if like shitwork.

Then make the loco as heavy as possible by cramming weight in literally every corner.
Now drill out the handrail holes, bend the top rails, glue them in place, then glue all the verticals in the holes and solder them to the top rails. There's also a horizontal bar in the handrails very low down, but I would just ignore it. see pictures
Now glue the detail bits on, lights, horns etc, note: when looking at the buffer beam, the flat buffer goes on the right, the curved one on the left.
For assembly pictures see the US version: https://www.thingiverse.com/thing:5988698