This is a jet engine you can use for a scifi plane.
The modelling was done in Blender. Exchange formats are exported from there. Objects and materials have reasonable names (not like Cylinder.000).

Object turbine housing procedural materials and maps are left as created procedural + painted. You can easily change several input parameters and values to change the base colour, or the amount and scale of the paint damage.
Some paint damage is procedurally generated and some paint damage is painted. The painted damage is based on a simple grey-scale texture. The edges are then procedurally scattered to make them hopefully look more natural.
All main input parameters are located in the INPUTS frame of the shaders.
Object turbine housing baked Only one principled shader is applied. Maps are baked into 4096x4096 images (colour, roughness etc.). You can use them for PBR shaders.
The main body and the exhaust fins are unwrapped as non-overlapping.

Enjoy!