I used to live in rural Aberdeenshire (real farming country plus heavily wooded areas) and my wife and I saw large black cats on a regular basis. This varied from crossing the road in front of the car at night or early morning, to walking boldly past the local nursing home in broad daylight.
My best sighting was this large black panther checking out rabbit holes in a line of gorse about 200m away. The tail swished and moved, and was held like a large cat and not a domestic. It was pure black with huge shoulder muscles. I watched it through my monocular for about 5 minutes before it went through a gap in the gorse and walked off down a field. I was just glad my dogs didn't see it. That might have been one cat chase that would not have ended well!
Not far from that sighting location, and about 400m higher, I came across prints in the snow later that year. These were cat prints (no nails) and I have a photo somewhere with my Nokia phone next to it for scale. These prints did not belong to a domestic cat. I'll see if I can dig them out.
A friend of mine owns a trout fishery in Aberdeenshire and has seen a panther many times. Walking back to his car at dusk one night, along the path that has a stream on one side and the loch on the other, he became aware of being watched. Across the stream, walking at the same pace was what he described as "a big black cat, like the one in Jungle Book". He made it to the car!
Months later, an angler in a boat on the loch was talking to the owner and pointed out that there was a very large cat across the stream and was the owner aware of it. All the owner said was "oh, he's back then"! The angler refused to get out of the boat for another hour or so!
There are many stories like this, all from reliable people. Like the one that was shot in the 50s and laid on a hay bale. The bail was just big enough to take the body, but the head and tail flopped off both sides...
Whether you believe any of this or not is up to you, but I can only report what I have seen or heard from people that I know would not make stuff up.
All I can say is that it is one of the prettiest large cats I have ever seen. My wife and I were in Dallas a few years back and went to the Dallas World Aquarium. We stopped dead in our tracks and looked at each other when we came to the panther enclosure. My wife just said "that look familiar babe?"
Cheers