Didn't do Triple as I did C3, P3 and B3 in Year 10 so I don't know about them. But for Double C2, P2, B2 I'd say:
C2 - Easy but Chemistry never really has ever had that high grade boundaries (always easy but grade boundaries always generous) and the 6 markers weren't exactly a walk in the park so I'd say maybe 48 A* / 42 A
B2 - Medium difficulty so I'd say on the levels of March 2013 which was 45 A* / 40 A
P2 - To be fair P2 wasn't so bad, but people always seem to find Physics hard and I can't really remember what the exam was like but I remember it being the hardest in my opinion so I'd say 42 A* / 35 A same as June 2013
I think your ones are quite reasonable but loads of people had different opinions on the exams.
I think I'd get
C2 - A, B2 - A, P2 - B, C/A - A
So an overall low A for Additional Science
C1 - A*, B1 - A, P1 - B, C/A - A
Probably a high/mid A for Core Science