if you make your own, start by 3D print the piece then Laser cut the plate.
it's easier and faster to edit & iterate on the laser cutter, and edit the tolerance of the svg file than modify an stl file for your 3D printer.
if you want to know more i made a video about how i did it here :
Thanks Selina! , i'm making a new version in wood & acrilyc this week :)
if you have a cnc near you you'll be able to have a better version in few days ;)