G'day Cockney,
I have a library of over 300 herpetology based books.
A Complete Guide To Reptiles of Australia, Swan and Wilson, 2003 - "Extremely variable, with small fragmented head scales". "M.s.spilota (Diamond Python) is dark grey to black with a cream spot on most scales, and clusters of all cream or predominantly cream scales arranged to form roughly diamond-shape blotches over back and flanks". On the Morelia spilota complex, it says "It remains to be demonstrated whether these represent valid ssp. (subspecies) or mere colour variants, but collectively occupy the most diverse habitats of any Australian python". On their locality, it says the occur in Eastern NSW and North Eastern Victoria.
Pythons of Australia, Geordie Torr, 2000 - "The carpet/diamond python shows the largest degree of geographic variation of all of the Australian pythons". It also says "Although highly variable, both within and among the different subspecies, all forms are quite robust snakes with a large head that is distinct to the body". More specifically, "The most distinctive form is the diamond python. The body colour is dark grey to black, with most of the body scalesbearing a small cream spot, giving the snake a speckled pattern. Clusters of scales with more cream on them form roughly diamond-shaped blotches on the dorsal surface - some are almost black, while others are distinctly yellowish".
Snakes of Australia - Dangerous and Harmles, Mirtschin and Davis, 1992 - "Consists of the subspecies, but there is as much variation within the individual subspecies as between them" On M.s.spilota "Dorsally, dark grey to black, with most scales having some cream. Clusters of entirely or almost entirely cream scales forming approximately diamond shapes are located the full length of the body, often in longitudinal rows".