Dash,
Its a bit early for me, so sorry if I'm missing something. You were commissioned at 18, but I'm not sure how your peers will end up with a different pension benefit to you. Reflecting the 3 'non pensionable' years you refer to, AFPS 75's overall accrual rate was l/68th of pensionable pay (1.47%) for officers but only 1/74 (1.35%) for ORs. AFPS 05 has just one accrual rate of 1/70 (1.43%).
Hope that helps? If you like, PM me.
Regards,
Al