I have the design files (SVG and DXF) for the 200x200 bed mount I'm using in my fork of the repository at:
I used the SVG file with a laser cutter to make my bed mount. The blue lines were used at lower power to etch the logo into the bed, and are optional. I used 1/4" melamine-faced MDF, which looks a little nicer than plain MDF. Here's how it looks installed:
I am using the MK3 aluminum heatbed, but this will also fit the 200x200 MK2 PCB heatbed.