Western Australian Big Cats

In approx 1978, my wife and I were travelling on a track between fishing spots on ######## Station in the Pilbara, the area nearby is known as the eighty mile beach. We had just went through a gate when a very large black cat stepped out of the bush some 35/40mtrs in front of us and stood looking at us, we stopped. I have said that the height would have been at least as large as our leggy dog but a fair bit longer in body with a tail in proportion. It was a beautiful looking jet black cat, obviously in very good nick and glossy, as mentioned to paper- no rosettes or any other colours present. The cat had a supple looking body and it’s head did not seem small as in some puma pics- but not oversize either .It was not panicky but watchful, the time of the day was perhaps strange, being around midday, after prob some 20/30 seconds it walked away into the scrub. I had a shotgun behind the seat of the utility and we discussed trying to have a shot at it, but it was too far to shoot with any certainty. As a note, I am and was an experienced shooter and shot many feral cats and foxes along this area, some of the cats were large in comparison to domestic animals, mostly all tabbies with a little ginger, very seldom any other colour.
The other comment regarding cats is listening to sounds at night whilst spotlighting foxes along the De Grey River roughly within one or two years of the sighting. I and friend hat just taken an old roo for meat (approx. 2am) in sandy hummocky spinifex flats adjacent to the river and were cutting and bagging the meat, when a very strange call got up- firstly a low coughing noise that went into loud grunts followed by a growl, then the growl became high pitched and ended up with a scream, then stopped and repeated as explained. Shining the light around did not reveal any animal, the racket did put the wind up us and the dog who was used to hunting was frightened. We did drive the area with light, but came up with nada. Later in time I did read a book that outlined a puma call that closely resembled the cries we heard. As mentioned to paper, I have heard all the noises that animals and birds make at night and nothing was remotely like this.