Send the form...attach a note and the evidence i.e. the part of lasors or whatever document speaks about the exemption.
Also ring the CAA and get someone to tell your and get them to email you it.
I also had a similar issue with regard to getting results transferred...one authority always seems to try give the work to the other authority involved so i had just rang both and got what I needed in writing from both parties.
Basically get every last bit of backup you can when dealing with two authorities because then no one can turn around to you at the end and say no actually wait you cant do that!