I believe the Class 1 turns into a Class 2 after one year, then I think you have fours years of Class 2 before that runs out - thats if my memory's correct??!
If you do speak to the CAA, please post their response Nottelling, as it would be interesting to know. My Class 1 ran out end of Aug and I think im "running on" Class 2 now!
G-ANDY