If you're like me, you've probably misplaced or outright lost a few screws when disassembling various computers. Often, the machines I've inherited also come with a mish mash of various screws that the previous owners used to substitute. Some of the substitutes are too long for the application and end up damaging the case exteriors.
Finding the right ones for the plastic case applications can be tricky and they're not likely to be at your local hardware store. The trick is, screws intended for plastics have much wider thread pitches. The threads are also different than what you'll find in wood screws as they are designed to be self-tapping but with a more machine screw style head. Most of the Commodore gear I've worked are T6 heads which you probably already have a driver for. The M3 size also seems to be the as-designed configuration.
After research and testing to find a good replacement, I've come to the conclusion that the best available screws for the application can be ordered easily from McMaster Carr and arrive in just a few days if you're in North America. You'll need a few different lengths in your kit and I would recommend 6, 8, and 10mm lengths for options. One caveat: the thread spacing on many of the original screws is actually a bit wider in pitch. This hasn't been a problem for me yet and has reliably screwed in and out without damaging the existing threads or needing excessive torque.
Have you found alternatives that you prefer? If so, share them here!