Please note that objects 1.10, 1.10.1 and 1.10.2 are essentially four objects each, combined for convenience yet still can be easily split by loose parts into individual meshes if you need to.
Please also note that mounting rails are quite high-polygonal models (suitable for whatever close-up look youd wish), thus depending on your scene, removing unnecessary pair of them (or even both) would reduce overall polygons count significantly.
All objects are grouped into single group for easier appending / linking.
All procedural PBR, based on Principled shader, thus compatible with modern PBR renderers. No textures used.
UVs unwrapped for extended use.
All imagery is done via Cycles / Filmic (Base Contrast profile), no post-processing.