Of the 4 extra countersunk screws I measured:

Length: 3.39mm
Diameter: 1.87mm
Head Diameter: 4.5mm

L: 3.44mm
D: 1.89mm
HD: 4.5mm

L: 3.50mm
D: 1.89mm
HD: 4.5mm

L: 3.51mm
D: 1.88mm
HD: 4.61mm