See drawing with additional dimensions. I have a Magura flatmount which is standard flatmount 34mm. and using 160mm rotor. I used a 3d-printer and made different designs and ended up with 7mm thick plate and positioned the slotted holes to minimum size and dimensions for aesthetic reasons.

This is the drawing I made for my Klein Attitude Comp.
Edit; correct dimensions and final design



I changed the size off the bolt holes and made small adjustments to fit perfectly on my bike. unfortunately I can’t share the files here as this forum doesn’t allow this to be uploaded. But you can easily draw it yourself.

Hi, also interested in this adapter. Are you able to share the .stl file in order to have one locally machined here?
Thank you