Well done on your mock grades!
The Govt is talking about getting rid of all coursework soon, apparently it doesn't help you learn. Which I agree with sort of but it also helps you gain a couple of marks if you're not too good at exams. And as you say, you'll have actually revised a bit for your main GCSEs so you should go up by at least a grade in all your subjects.
Trouble is, there's always distractions so not that many get round to it - hopefully you will though!
I can't remember whether I went up or down and if so in which subjects between my mocks and the real thing. I did mine last year and in my mocks I got something along the lines of 1 A*, 3 As and 5 Bs.