Old house, circa 10yrs.
I had a look at it last night and couldn't see any screws so I presumed it was plastered/glued in place. I'll have a closer inspection this evening with a torch.
I'm not sure what kind of rough effect I have either. It looks like the plaster was wet and you pressed a trowel onto it and lifted it. You'd have lots of little troughs and hills on it. I seriously doubt it was done this way though as it's in an estate and I can't imagine the builders going through this hassle when building it and it sounds much more likely to be painted on, although I have no idea how.
Edit: I just googled the three you mention and it looks most like sponged plaster which means I will need to get a plasterer in??
Is it possible, I wonder, when I remove the rose that this plaster is actually behind it or is that wishful thinking???