Sorry I did a ninja edit saying he’s also been around here for years (though that doesn’t necessarily mean he couldn’t be neglected or in need of help).

I’ll have a closer look at the colour of the eyes just in case they used to live around my area and ran back or somehow got this far from home. But this visitor cat has a few tiny white hairs like the barest graze of a paintbrush. One brush on top of the head, one on the chest like a locket, and one on the belly.

He or she is quite a large tall cat, has a deep mournful meow but is usually silent, and seems quite comfortable and friendly roaming around and rolling for pats. There isn’t a hanging belly (primordial pouch) and despite their size they look long and very slender. The face/muzzle is more slim with a large square looking nose. Your friends cat has a rounder bigger muzzle with a smaller nose.

I can try to get a good photo of this cat here and give it to you but the cat in the photo doesn’t look the same :(

Edit: If your friend is desperate though I can try to catnap visitor cat to the vet which would allow ID and collection from a shelter if it’s theirs? I just don’t want to risk accidentally kidnapping a neighbour’s cat