ataxian
PALE BLUE DOT
I had some small screws that held my SCANNER together for the CNC machine I had. I lost a couple and had to order $20 worth of screws.I'd take another one out and take it to a Fasco fastener outlet or a good hardware store to try and match up. They are a self tap thread but a normal screw should be OK if careful.
Keep it in a piece of tape in your wallet so you don't loose another. Keep in mind while out and about.
Good luck.
At this point I will just use the unit missing a screw. I thought you might know off the top of your head? I like your ideal of putting a piece of tape on one and bring it to a hardware store.