No way this is Red-legged, much too dark and I suspect this was taken at around 2800m at Kumul Lodge, way out of range of the Red-legged. I am not sure if these are Calaby's or New Guinea Pademelon Thylogale brownie…..
It appears to be a Red-legged Pademelon probably the subspecies orimo, found in New Guinea...
Information taken from Wikipedia---
The Red-legged Pademelon (Thylogale stigmatica) is a species of small macropod found on the northeastern coast of Australia and in New Guinea. In Australia it has a scattered distribution from the tip of Cape York Peninsula in Queensland to around Tamworth in New South Wales.[3] In New Guinea it is found in south central lowlands.[4]
The Red-legged Pademelon is usually solitary but may group together when feeding.[5] It is found mostly in rainforest, where it is rarely seen, but it is not considered threatened.[2] In New South Wales, however, it is considered to be vulnerable.[6] It feeds on fallen fruit, leaves and grasses.[3] It weighs 2.5 to 7 kg and is 3858 cm long with a 3047 cm tail.[5]
There are four subspecies of the Red-legged Pademelon:[1]
T. s. stigmatica, found in the Cairns region of Queensland;
T. s. coxenii, found in Cape York Peninsula;
T. s. orimo, found in New Guinea;
T. s. wilcoxi, found in southern Queensland and New South Wales.[4]