I asked the same question via email and got this response. The problem is we need the linear not modular and I also need the mark schemes which we dont have. However, if you need the modular here it is
The grade boundaries for June 2008 modular were:
Paper 12: C = 46, D = 37, E = 29, F = 21, G = 13
Paper 13: C = 49, D = 39, E = 30, F = 21, G = 12
Paper 14: A* = 54, A = 46, B =36, C = 26, D = 14, E = 8
Paper 15: A* = 53, A = 45, B =34, C = 23, D = 12, E = 6
If anyone has the mark schemes and could put them on here I would be v.grateful