Thanks for the information and pictures, I find this very helpful.
**Update**
I followed the instructions and redid the tractor (1-piece prop). I turned out well but I am still trying to figure out how to convert the original DDS file in Photoshop. I have the DDS plugin but there are so many damn settings.
The DDS files can be a pain in the neck. When we did the BGH and GSH conversions for LOSV, Reini gave me a screenshot of the settings he used in Photoshop to convert the TGA tiles to DDS. Until he did that I had no clue and my settings would cause you to fall through the tiles when you entered the game.

Perhaps Reini's settings will work for me if I can find them. Otherwise I may have to go Paintshop and get up to speed from you on that.
For now I took truck.dds from TW and renamed it tractor_c.dds. As expected it shows up all messed-up on the tractor but at least the texture is visible. Bullets do not go through it.
I think the bullets problem you are seeing is due to the DDS file, another possibility is that I exported the 3DS to Kuma and earlier Z3D. I figured the DD1 objects loaded fine in EWV so making the new objects Kuma and earlier is not a problem.