So far, the guy named Overrich from South Korea was the only reliable supplier of sturdy MSX cartridge cases. But recently we've got some competition! The RBSC's authorized Carnivore2 manufacturer RetroGameRestore from Taiwan has just produced a bunch of nice-looking and sturdy cartridge cases.
There are 2 different models: one general-purpose case and the other - the custom case for Carnivore2. So if your Carnivore2's case is somehow broken or you don't like it anymore, you can easily order the replacement and you won't even need to cut any holes in it. Your board will fit into it perfectly. There are 2 different colors available: clear-transparent and smoked-transparent:
The good thing about these cases comparing to Overrich's ones - they can be closed without screws. The two halves have grooves and they "click" into each other when joined. This is quite useful when you need to periodically take the board out of the case for reprogramming or for adjustments (good for developers).
You can purchase the cartridge cases directly from RetroGameRestore:
http://retrogamerestore.com/msx_cart_shell/
http://retrogamerestore.com/carnivore2_shell/
According to the manufacturer, the following screws should be used for the cases:
https://aliexpress.com/item/32949246224.html