I know it's old school but a 782 gear cartridge belt addition could free up a lot of space in that pack, plus lighten it a bit.
We had the option of magazine pouches for extra magazines, bayonet scabbard, holster w/sidearm and magazine pouches for it (.45), canteen, first aid kit, and probably some other stuff that I'm forgetting.
All in all, it was a pretty good system.
What say you, Paul?