Good thread, I have a few to add.
The feet on my compressor are the upper A-arm bump stops off of early 70's GM cars.
I bought a magnification light at a garage sale for 2.00 but the base was broken. I welded some one inch strap around the cast base and when it cooled off it shrunk to a very tight fit. I used a aftermarket oil cooler bracket to mount it to my workbench, this makes it easy to remove if its in the way.
I repurposed some BMX bicycle stunt pegs for side handles on the angle grinders I put wire wheels on. I like the extra weight they add and they are a bit more durable than the plastic ones, or at least the plastic ones that come on HF grinders.
Besides the aircraft floorboards my cart was built around, the metal all came from a commercial clothing rack and the bottle holders are aircraft seat belt extensions. Like the ones the flight attendants show you during the safety announcement at the beginning of each flight.