Bit of an update...
Patch is having trouble getting used to Billy's shouting, bless her. She gets cross with him and then that makes her anxious. She seems to like the little Pet Remedy spray I got in her bed / blankets though. Calms her down pretty well, so will order a bigger spray. Kitty ( her Mum ) is coping better and has more patience. Perhaps it comes from being a Mum! Neutered after Patch and her brothers though, and Patch was neutered as a kitten.
Billy is good with the girls, and backs off from trouble. He goes out to his pen daily too where he sees Tompuss ( in another pen ). Tompuss and Billy like each other, but Tom made it obvious at a brief meeting that he doesn't like Billy in HIS pen!!!

Gotta love him! He's more of a people cat really.

We thought they might get on, but maybe in Billy's pen one day. Or maybe we'll join pens with a closeable cat door. Will leave that for now though...