Simple Clamping system for crafting corners

I wanted a simple system to hold 3mm plywood in place for a dolls house kit I am building. I have used 8mm x 3mm magnets in 3D printed blocks to clamp the parts at right angles to one-another. I found it easier to make the right angle in two parts and glue them together rather than trying to print it as one part because with the right settings on my printer there was almost no post-processing required. Just slot two magnets into each part making sure to reverse the orientation of the magnets so