thanks all for the feedback so far - all I can see is a big black shadow now - I wondered if anyone could give me some advice on the AO pass, it was my first time doing one and I wasn't sure if i should do it with the glass hidden or not, in the end I went with the glass hidden so there was more shadow detail in the inside part. I think the contact shadow issue might be a mip matte shadow issue, its quite dark on the beauty render.