Downloaded Items appear bizarre

I have downloaded-
1) a building (Brandenburg Gate) of which parts are pitch black
Why does this happen and what do I need to do to make the building look real?

2) A Russian P36 steam engine with no sound.
Where do I find the sound?

3) An Italian 740 class steam locomotive from TrainzItalia, with wheels that turn backwards when the loco rolls forward, and the horn sound of an electric loco.
How do I fix that?

4) German DRG doubledecker carriages without wheels and various old DR diesels without wheels
How do I fix that?

What version of Trainz and what build do you use?

Trainz 2009
Version 3
Build 38411

The only advice I can offer is to pull up each item in your CM2, RMB click and check for errors and missing dependencies.

You can pull up all your faulty items in CM2 by using the "Faulty" filter in the lower left area, and you can list all your items that are missing dependencies by using the "Missing Dependencies" Tab in the main window area.