I heard talk quite a while back about so-called QLD rainforest diamonds. I think you'll find someone has introduced a hybrid to the world and called it this. True diamonds are cooler region animals.
The diamond/coastal "Port Mac" pythons aren't the only pythons to be considered intergrade. This word is widely used and inaccurately points only at the diamond/coastals of the Gosford-Nth NSW regions. Intergrades are a sub-species of two species where their regions overlap, and have adapted to conditions at either end where conditions might start to get a little harsh for two species involved. Diamonds like the cooler regions, coastals like the warmer regions. In between you have their natural hybridised cousins who take up the climate in between. But also, your murray darlings, who take up big area inland, can overlap the diamonds and coastals, too. I've never heard of anybody having a murray/coastal intergrade but that's not to say they don't exist.