Darts Scoreboard Chalk Tray (Parametric)

I have an old chalkboard scoreboard for darts games like cricket and *01, but the little chalk holder it came with is flimsy and annoying to use. I've seen scoreboards like this one in other places so I expect it will fit many scoreboards, but the design is parameterized so you can customize the cutout based on the thickness of your board, as well as the width and size of the tray to fit different sized chalk. The cutout can also be flipped so the tray can clip to the top or bottom of the scoreboard.

My board measures 3.0mm thick so I added a .25mm tolerance to the cutout and it holds nicely; I found sliding the tray on sideways is easier than trying to push it straight up/down.

Nothing special wrt. print settings; I used PETG because my board is outdoors, but I'm sure PLA would work too.