This is an old project that I decided to revisit again.
I left it after I finished the uvw unwrap, here it is the new unwrapped model ready for texturing. For this process, I not only used 3ds Max tools, but also a plug-in called TexTool.
And this is how the new unwrapping map looks like.
If everything goes according to plan I should texture the crane truck using Substance Painter.