Yes, you are right ! --------------------- you dunno wat WW2 SBO
is
What you have got is the old style SBO - probably with 2 ammo
pouches that can take 4x30 round magazines with room for two
grenades at the side of each pouch, right?
There are even older pouches issued earlier, each ammo pouch having
3 compartments that each hold 2x20 round magazines.
While I have the above, I do not have the WW2 SBO, but I do have
the ammo pouches - they are just an oblong pouch with a single
compartment that is about 2.5 in deep, 4.5 in wide and 6.5 in high
that allows chargers with .303 rounds to be carried.