Too Old Too Soon,
I believe that although your terms were changed from 16/38 to 18/40 on signing for a PC from a SS you can still PVR to exit at the 16/38 point and retain and immediate pension and gratuity although it would be abated slightly due to the early exit. Try it on the calculator with an exit date 2 years early. It appears this way for my other half which is what we are banking on!!!