How to get that worn look?

[Frog]

When I used Laser Vellums, I could easily distress the actual "film" making it unique.

And, not to take anything away from Jon, but the two voids in the lower left quadrant caught my eye (and memory) as the same filter that Ryanet offers.
That one is out there in a few locations.

[Screened Gear]

Frog you maybe right. I have a few and some I have created from scratch. That one was in my files I may have downloaded it to see what it looked like. Wait I will post a new one soon.

[Screened Gear]

Ok I found the image I up loaded at these places...

www.toonvectors.com
yaymicro.com
depositphotos.com
www.zoonar.com
www.thinkstockphotos.co.uk

So now I have no idea where it came from. The file I have is vector rendering of the raster file that is found at all these places. Can't tell you how I got that file now. I am going to get rid of it now. I don't think I have used this one on any client work.

[Rockers]

There are plenty of distress texture packs at www.creativemarket.com. Both for photoshop and illustrator.
For example this one
https://creativemarket.com/GraphicMonkee/50730-Easy-Distress-Texture-Pack
or this one
https://creativemarket.com/BlueLineDesign/16751-20-Distressed-Textures-and-Brushes
or this
https://creativemarket.com/RuleByArt/42773-Vector-Bundle