Johnstone'sMist coat won't make any difference to top coat as long as it wasn't vinyl watered down!
What is the make of your paints? Ceiling and walls. Please put a picture up.
Also have you already bought the vinyl paint?
Bought the vinyl. Put most of it on it's just the kitchen where I'm wondering whether to put it on. As it's exactly same colour as mist coat so wont see if I've not covered every bit. And different sheen might come through. Am I over worrying?
Ceiling is just contact mist coat and top coat of contract. I was gonna leave it like that. It's the cutting in on ceiling which is a bit dark . Just keep going over it?
Also, what product would you use to fill this old socket casing?