Service past 55? How about FTRS where you can work to 60? There is also rumour that this will be extended to 65 in the near future...
Here's a link
RAF Reserves - FTRS Vacancies
Also, you start to earn a new pension under RFPS05 which is 1/70th of your final FTRS salary for every year you work. Most FTRS contracts are 4 years long.
Good hunting
LJ