I was a Regular on AFPS75 after 21.95 years - I retired on a Friday and then joined on FTRS(HC) terms on the Monday. I got my full pension (less abatement to ensure I didn't earn more than I did as a Regular - even though I dropped a Rank) and also I got my full gratuity plus resettlement commutation. I had a gap of 2 days and I got everything owed (less the abatement).
This was just over 1 year ago. I understand that the rules changed to not needing a 30 day gap after AFPS75 closed to new entrants? It is most surely closed now so they cannot hold you to 30 days as before.
Enjoy
LJ