DB, I'm afraid that the astigmatic component of your prescription (the CYL part) is probably too large for a class 1. The initial limits are 2 dioptres.
Good job on writing to the CAA, thats definitely the best way. If you want a quicker response, (the CAA may take a few weeks to respond), you can take the following document to an optician to get their opinion.
Cheers
http://www.caa.co.uk/docs/49/SRG_MED...%5B2189%5D.pdf