This is slot cover for Retro 8 bit PC : MSX2 FS-A1.
A lot of the old MSX2 FS-A1 users had been lost the cover,
So I am glad to help them.
Cover_with_Notch.STL : you can open the door with easy. :D
-- thank you for good idea : TabajaraLabs!
I think that FS-A1 Mk2 and FS-A1F could be used with.
Hint) If you want to get the surface with flat color,
Print over the (paper) masking tape.