Same question to the one that supplied your Shoebox, would be prudent?
I can’t seem to locate my thread gauge for confirmation, but based off some quick measurements with digital calipers I’d say they are #10-32 stainless button head.
https://www.mcmaster.com/98164a459
I kept losing the screws so I use a couple of high strength magnets to hold the cover in place. Works great and allows easy access.![]()