These screws need a jeweler's screwdriver or similar - round Phillips head. Metric dimensions are nominal and specified as Overall Length x Shank Diameter Under Head x Head Diameter. See below for size and gauge code.
Roves are slightly conical, solid copper washers which are used in boatbuilding to make a peened rivet joint. Insert the correct gauge copper nail and push a rove over the tip, cut off excess nail and set using either a ROVE PUNCH or the ball side...