In 1940 John Ash retired as government printer and W.C.G. McCracken took up Ash's former position. In 1949, 2 years after the death of John Ash, he printed the last of the half-penny wallaroos; instead of commissioning a new set of dies; he used the original dies.
Before he printed with the 1938 dies he removed the Ash imprint and then substituted the imprint with his own name.
The usage of the original die caused three forms of plate cracks, the first, the very early cracked plate has been authenticated as the only one known (it does not have a perforation pip (no dot at bottom centre), and two others, an early plate crack and a late plate crack.
Pictured is the only known complete set of 1949 state of plate cracks from a 1938 die on thick paper (all of McCracken's official paper is thin).
The rare very early state of plate crack without bottom central perforation pip
The scarce early state of plate crack with bottom central perforation pip
The scarce late state of plate crack with bottom central perforation pipHe also re-used 1938 dies to reprint a few Coronation robes in 1949 along with the new 1949 dies with the new imprint, and in one printing of the half-penny wallaroo with coil perforation, a wrong ink mixture was used, there is only 160 of those stamps recorded, nicknamed the "mellow-yellow" roo.
All "1938" issues with the McCracken imprint were printed in 1949.
Around 1942, McCracken removed personalised imprints altogether. The impersonal 'by Authority' imprint was born, much to the disgust of collectors at the time. It was his decision to do this, but something he denied until many years later.