Some of my metal (/,,/) work for Poliigon.com
100% procedural using Substance Designer.
Get the textures on Poliigon: https://www.poliigon.com/search/recent/narrow/new/metal
Old Bronze Repolished
Old Copper Repolished
Old Heavily Corroded
Rust, Repolished 
Engine Turning 
A tool I made to generate Scuffs
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