I apologize in advance, I will write in English because it is easier to explain.
We all know that texturing is a nightmare, especially if we have more textures than one model (more forms of the same locomotives, the same wagon ...). Until now, I've met several times with multiple texture files but I have never dared to do something like this. I'll tell again ... banbyggarna.stl. It's good when someone does something and shares it with the community, and some things really are not hard to learn. Yesterday I downloaded a Swedish Asea (from, of course, banbyggarna) that was made to have one mesh but because it has a lot of textures. Result is this ...
but more textures
they can also be changed through a separate window
and this is my attempt
you can change almost anything through the window ... plough in two options, bumpers in three optiions ... skins
follow second locomotive