Gut shot.
The switch is for symmetrical clipping (which is the stock design hence the S) and Asymmetrical clipping (mod). The stock setting is just a couple of zenner diodes in parralel and the mod is a 1n4001 and 5mm LED in parallel.
Enclosure was powder coated at home, then I had a friend screen print it, then I put clear powder over that at home.
The result is a very durable finish and powder coating takes around 2 hours between both coats from start to finish (based on both cure time and time it takes to cool after it's baked on).