Thank you all for your input. It is an 11mm.
I don't prefer SOR diagrams either it was just the one I had in front of me at the time and other official one wan't giving any better info.
I've searched high and low for the Toyota Part Numbers for the Nut and Washer that go with the Studs from the Parking Brake Drum (Part Number 90114-11124). Anybody happen to know what they are? Nut and washer for number 16 in the image for reference. Any help would be much appreciated. Thanks.