Chain Guard for Shimano Nexave (4 mounting holes)

The chain guard on my dad's old bike (25 years old) broke, so I decided to design a new one and 3D print it. For some reason, it turned out the mounting holes for the chain guard weren't equally spaced, so I took a photo of it and based the design on that.
I printed it in PLA (since that was the only filament I had), and it seems solid enough to me, considering no real stress will be put on the part.
The chain guard is designed for nuts to be put in the front holes (it may be a bit tricky to fit them, try sanding and cutting a bit) and the screws to be inserted from the back, making sure nothing is in the way when changing gears.