I wouldn't worry to much about you education history. Just say you had a general education, and took CSE's, you can mention the subjects if you like. I am not grades will overly matter.
I personally think that the most important information, is your work history. Have a look at this and see if it helps. I am in the same boat as you. My jobcentre have offered someone to come and help me with mine.
http://www.direct.gov.uk/en/Employment/Jobseek ers/Helpapplyingforajob/DG_173655



