Problems with importing after retexturing

[ReviLoxilef 0]

Hello there awesome people,

opening this question in hopes that I did not overlook a similar one.

TL;DR: Tried to retexture assets and failed...or made a mistake somewhere along the way. Why? Wanted public Transport to match.

To start with, I exported Thomas13TO's Grand Jet Cable Car and - with the help of numerous tutorials - went to work. After some completely failed attempts to import the retextured modle I finally managed to open it in the Asset editor...at least somewhat (this is scaled down to 0.1 in the Asset manager):

 

This mistake could be resolved after I realized that I used wrongly named textures which led to this:

Now it's got a texture (in the preview window), but it is on the inside for some reason and not the outside. I cannot say anything about the scale now, since it does not show up at all, when I click continue (see the right picture).

After reading through some answered questions and tutorials I still don't quite know what else to do and why it's not working properly. It's working fine in Blender:

Here are the parametres I use for the export. They are basically what the tutorial told me to do.

 

Thank you in advance, I appreciate any kind of help I can get and already apologize if I overlooked something rather obvious.

[Darf 1,439]

Your normals are inverted.