All About PCB Tooling Holes: What They Are and Where They Go | Blog | Altium Designer
Steve Jobs' Apple-1 Prototype PCB Goes up for Auction | Extremetech
Charging Connector Flex PCB Board for Tecno Spark Go KC1 by Maxbhi.com
Original second hand motherboard repalcement for PSP Go PCB mainboard Repair Parts for PSPGo Console Free Shiping|Replacement Parts & Accessories| - AliExpress
Just a sample of inspirational pcb design, and where lock washers should go, (proco Roadkill/Brat from 1996). : r/diypedals