My self imposed retreat worked; on Sunday around 6pm it suddenly occurred to me the story was almost complete so I typed like a maniac and (practically) finished the first draft! Over 38,000 words and just the tidy up at the end. I felt so relieved.
The next task is to tidy it up - check the final stages for errors etc then sit down with Alex Rider and Harry Potter and check the language and the tone against Adventures in Recordland. So basically I get to read (and dissect!) books. Excellent!