The block of 4 is an 1872 imperforate plate proof, the first printing of this stamp was between 1868 (pale blue) and 1871 (blue). A second plate of the 2d stamp was sent from England by Perkins, Bacon to the colony of Queensland in 1872 and was first printed in August of that year.
The new plate is helpful in separating many of the 2d printings up to 1879.
Plate II of the 2d issue may be identified by a smudged dot to the left of “U” in “QUEEN” and tiny dots near the lower curl of the arabesque.
This block of 4 in black was rejected and instead was issued in blue. There is only a few of these blocks known, this superb example has perfectly cut sides.
The Arabesque
Rob