Thanks for the replies. I did contact my school, but they could not tell me as it was so long ago. I managed to get a certificate from AQA, but maths wasn't on it. My old school friends informed me that maths was with the LEAG.
I did wonder if it was Edexcel myself until I saw the dates. Plus it's CSE and not GCSE like I want. I emailed Edexcel to ask if they held the records, but they said I would have to pay for them to even tell me that.