2D KitBash Library, version 1.0. It's meant for all those who use photo-bashing to create their concept art. This particular library version is meant for design of ground military vehicles, that is, it contains pieces taken from those. It might get updated in the future. New library versions/categories are on the way.
The content of the library can be seen here: https://www.artstation.com/artwork/evZWZ
The library comes as a Photoshop file, 203 MB in size.