The official drawing does not give the corner radius.
See my enhanced summary drawing, which reports my specimen measurement of 6.5mm corner radius:
http://www.truetex.com/raspberry_pi_dis ... nsions.pdf
If you are designing an enclosure, bracket, or bezel, be aware that the official drawing is incomplete because it does not specify tolerances for most dimensions. The corner radius is not given at all, so we can only invent our own specification based on measuring specimens. You have to design either flexibility/allowance/adjustments into your mechanisms to fit a best-guess as to how those tolerances will range from unit to unit. This matters if you intend your design to fit any given display instead of just the one in hand. If you guess wrong on critical but unspecified things like M3 screw penetration, then your design will not just have a fit problem; assembling it will actually destroy the display.